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Jiang JJ, Ma MS, Wei M, Qiu ZQ. [Investigation on the treatment of empagliflozin in glycogen storage disease type Ib]. Zhonghua Er Ke Za Zhi 2024; 62:526-529. [PMID: 38763873 DOI: 10.3760/cma.j.cn112140-20240301-00136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/21/2024]
Abstract
Objective: To investigate the safety, efficacy and effective dose of empagliflozin in the treatment of glycogen storage disease type Ⅰb (GSD Ⅰb). Method: This was a cross sectional study. A total of 28 children with GSDⅠb who started oral empagliflozin treatment from January 2021 to June 2023 in the WeChat group of patients with glycogen storage disease were selected as the study objects. Clinical data such as general situation, current situation of medication and adverse reactions of the children were collected through questionnaires from June 18 to 30, 2023. The differences of symptoms and laboratory tests before and after empagliflozin treatment were compared by using paired chi-square test and Wilcoxon signed rank sum test. Results: Totally 28 children with GSD Ⅰb were from 12 different provinces, autonomous regions and municipalities in China. There were 14 males and 14 females, Empagliflozin treatment was started at the age of 4.8(2.4, 10.8) years, the time of treatment was 14.5(11.3, 21.5) months, the initial dosage was (0.23±0.11) mg/(kg·d), and the maintenance dosage was (0.28±0.12) mg/(kg·d). Empagliflozin showed positive effects on neutropenia, severity of inflammatory bowel disease like symptoms(Z=-3.70, -2.65, both P<0.05), The proportion of recurrent oral ulcers, recurrent bacterial infections and anemia was significantly lower than that before medication 18% (5/28) vs. (46% (13/28), 14% (4/28) vs. 46% (13/28), 21% (6/28) vs. 46% (13/28), χ²=4.05, 5.26, 3.05, all P<0.05). GCSF was once used in 5 children with GSD Ⅰb, all of them had completely stopped GCSF after empagliflozin treatment. The most common adverse events during empagliflozin treatment were hypoglycemia (5 children) and urinary infection (3 children). All 28 patients had no serious adverse reactions. Conclusions: Empagliflozin can increase the neutrophil count of children with GSD Ⅰb, and had a favorable effect on symptoms such as recurrent oral ulcers, and recurrent infection. The common adverse events during empagliflozin treatment were hypoglycemia and urinary infection.
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Affiliation(s)
- J J Jiang
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - M S Ma
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - M Wei
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Z Q Qiu
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
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Liu C, Wang J, He W, Zhang C, Zhang S, Yuan S, Hou Z, Qin M, Xu Y, Gao X, Peng Y, Liu K, Qiu ZQ, Liu JM, Zhang X. Strain-Induced Reversible Motion of Skyrmions at Room Temperature. ACS Nano 2024; 18:761-769. [PMID: 38127497 DOI: 10.1021/acsnano.3c09090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
Magnetic skyrmions are topologically protected swirling spin textures with great potential for future spintronic applications. The ability to induce skyrmion motion using mechanical strain not only stimulates the exploration of exotic physics but also affords the opportunity to develop energy-efficient spintronic devices. However, the experimental realization of strain-driven skyrmion motion remains a formidable challenge. Herein, we demonstrate that the inhomogeneous uniaxial compressive strain can induce the movement of isolated skyrmions from regions of high strain to regions of low strain at room temperature, which was directly observed using an in situ Lorentz transmission electron microscope with a specially designed nanoindentation holder. We discover that the uniaxial compressive strain can transform skyrmions into a single domain with in-plane magnetization, resulting in the coexistence of skyrmions with a single domain along the direction of the strain gradient. Through comprehensive micromagnetic simulations, we reveal that the repulsive interactions between skyrmions and the single domain serve as the driving force behind the skyrmion motion. The precise control of skyrmion motion through strain provides exciting opportunities for designing advanced spintronic devices that leverage the intricate interplay between strain and magnetism.
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Affiliation(s)
- Chen Liu
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000, P. R. China
| | - Junlin Wang
- School of Integrated Circuits, Guangdong University of Technology, Guangzhou 510006, China
- School of Physics, Engineering and Technology, University of York, York YO10 5DD, U.K
| | - Wa He
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000, P. R. China
| | - Chenhui Zhang
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Senfu Zhang
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000, P. R. China
| | - Shuai Yuan
- School of Mechanical and Electrical Engineering, Guilin University of Electronic Technology, Guilin 541004, P. R. China
| | - Zhipeng Hou
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, P. R. China
| | - Minghui Qin
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, P. R. China
| | - Yongbing Xu
- School of Integrated Circuits, Guangdong University of Technology, Guangzhou 510006, China
- School of Physics, Engineering and Technology, University of York, York YO10 5DD, U.K
| | - Xingsen Gao
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, P. R. China
| | - Yong Peng
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000, P. R. China
| | - Kai Liu
- Physics Department, Georgetown University, Washington, D.C. 20057, United States
| | - Zi Qiang Qiu
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, United States
| | - Jun-Ming Liu
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, P. R. China
- Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 211102, P. R. China
| | - Xixiang Zhang
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
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3
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Zhang ZJ, Qiu ZQ. [Diagnosis and treatment of pediatric Gaucher disease]. Zhonghua Er Ke Za Zhi 2023; 61:955-957. [PMID: 37803870 DOI: 10.3760/cma.j.cn112140-20230807-00086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 10/08/2023]
Affiliation(s)
- Z J Zhang
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Z Q Qiu
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
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Jiang JJ, Zheng X, Ma MS, Cui XG, Jian S, Tang XY, Bao XD, Zhang SM, Ma JR, Song HM, Qiu ZQ. [Short-term efficacy of empagliflozin in children with glycogen storage disease type Ⅰb]. Zhonghua Er Ke Za Zhi 2023; 61:515-519. [PMID: 37312462 DOI: 10.3760/cma.j.cn112140-20230131-00067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Objective: To analyze the short-time efficacy of empagliflozin in the treatment of glycogen storage disease type Ⅰb (GSD Ⅰb). Methods: In this prospective open-label single-arm study, the data of 4 patients were collected from the pediatric department in Peking Union Medical College Hospital from December 2020 to December 2022. All of them were diagnosed by gene sequencing and had neutropenia. These patients received empagliflozin treatment. Their clinical symptoms such as height and weight increase, abdominal pain, diarrhea, oral ulcer, infection times, and drug applications were recorded at 2 weeks, 1 month, 2 months, 3 months, 6 months, 9 months, 12 months, and 15 months after treatment to assess the therapeutic effect. The liquid chromatography-tandem mass spectrometry method was used to monitor the changes in 1, 5-anhydroglucitol (1, 5AG) concentration in plasma. At the same time, adverse reactions such as hypoglycemia and urinary tract infection were closely followed up and monitored. Results: The 4 patients with GSD Ⅰb were 15, 14, 4 and 14 years old, respectively at the beginning of empagliflozin treatment, and were followed up for 15, 15, 12 and 6 months, respectively. Maintenance dose range of empagliflozin was 0.24-0.39 mg/(kg·d). The frequency of diarrhea and abdominal pain decreased in cases 2, 3, and 4 at 1, 2 and 3 months of treatment, respectively. Their height and weight increased at different degrees.The absolute count of neutrophils increased from 0.84×109, 0.50×109, 0.48×109, 0.48×109/L to 1.48×109, 3.04×109, 1.10×109, 0.73×109/L, respectively. Granulocyte colony-stimulating factor was gradually reduced in 1 patients and stopped in 3 patient. Plasma 1, 5 AG levels in 2 children were significantly decreased after administration of empagliflozin (from 46.3 mg/L to 9.6 mg/L in case 2, and from 56.1 mg/L to 15.0 mg/L in case 3). All 4 patients had no adverse reactions such as hypoglycemia, abnormal liver or kidney function, or urinary system infection. Conclusion: In short-term observation, empagliflozin can improve the symptoms of GSD Ⅰb oral ulcers, abdominal pain, diarrhea, and recurrent infection, also can alleviate neutropenia and decrease 1, 5AG concentration in plasma, with favorable safety.
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Affiliation(s)
- J J Jiang
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - X Zheng
- Clinical Pharmacology Research Center, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - M S Ma
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - X G Cui
- Clinical Pharmacology Research Center, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - S Jian
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - X Y Tang
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - X D Bao
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - S M Zhang
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - J R Ma
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - H M Song
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Z Q Qiu
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
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5
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Qiu ZQ. Chirality dependence of spin current in spin pumping. Nat Commun 2022; 13:5229. [PMID: 36064722 PMCID: PMC9445075 DOI: 10.1038/s41467-022-32981-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 08/26/2022] [Indexed: 12/05/2022] Open
Affiliation(s)
- Z Q Qiu
- Department of Physics, University of California at Berkeley, Berkeley, CA, 94720, USA.
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6
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Xu N, Qiu ZQ, Zeng XJ, Li BQ, Zhang XM, Huang X. [Peripheral neuropathy caused by vitamin B 12 deficiency in a patient with glycogen storage disease type Ⅰa]. Zhonghua Nei Ke Za Zhi 2022; 61:1056-1058. [PMID: 36008301 DOI: 10.3760/cma.j.cn112138-20211001-00019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Affiliation(s)
- N Xu
- Department of Family Medicine & Division of General Internal Medicine, Department of Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Z Q Qiu
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - X J Zeng
- Department of Family Medicine & Division of General Internal Medicine, Department of Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - B Q Li
- Department of Family Medicine & Division of General Internal Medicine, Department of Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - X M Zhang
- Department of Family Medicine & Division of General Internal Medicine, Department of Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Xiaoming Huang
- Department of Family Medicine & Division of General Internal Medicine, Department of Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
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Zhu T, Ruan W, Wang YQ, Tsai HZ, Wang S, Zhang C, Wang T, Liou F, Watanabe K, Taniguchi T, Neaton JB, Weber-Bargioni A, Zettl A, Qiu ZQ, Zhang G, Wang F, Moore JE, Crommie MF. Imaging gate-tunable Tomonaga-Luttinger liquids in 1H-MoSe 2 mirror twin boundaries. Nat Mater 2022; 21:748-753. [PMID: 35710632 DOI: 10.1038/s41563-022-01277-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 04/25/2022] [Indexed: 06/15/2023]
Abstract
One-dimensional electron systems exhibit fundamentally different properties than higher-dimensional systems. For example, electron-electron interactions in one-dimensional electron systems have been predicted to induce Tomonaga-Luttinger liquid behaviour. Naturally occurring grain boundaries in single-layer transition metal dichalcogenides exhibit one-dimensional conducting channels that have been proposed to host Tomonaga-Luttinger liquids, but charge density wave physics has also been suggested to explain their behaviour. Clear identification of the electronic ground state of this system has been hampered by an inability to electrostatically gate such boundaries and tune their charge carrier concentration. Here we present a scanning tunnelling microscopy and spectroscopy study of gate-tunable mirror twin boundaries in single-layer 1H-MoSe2 devices. Gating enables scanning tunnelling microscopy and spectroscopy for different mirror twin boundary electron densities, thus allowing precise characterization of electron-electron interaction effects. Visualization of the resulting mirror twin boundary electronic structure allows unambiguous identification of collective density wave excitations having two velocities, in quantitative agreement with the spin-charge separation predicted by finite-length Tomonaga-Luttinger liquid theory.
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Affiliation(s)
- Tiancong Zhu
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Physics, University of California, Berkeley, CA, USA
| | - Wei Ruan
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Department of Physics, University of California, Berkeley, CA, USA.
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai, China.
| | - Yan-Qi Wang
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Physics, University of California, Berkeley, CA, USA
| | - Hsin-Zon Tsai
- Department of Physics, University of California, Berkeley, CA, USA
| | - Shuopei Wang
- Beijing National Laboratory for Condensed Matter Physics, Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing, China
- Songshan Lake Materials Laboratory, Dongguan, China
| | - Canxun Zhang
- Department of Physics, University of California, Berkeley, CA, USA
- Kavli Energy Nano Sciences Institute, University of California Berkeley and Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Tianye Wang
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Physics, University of California, Berkeley, CA, USA
| | - Franklin Liou
- Department of Physics, University of California, Berkeley, CA, USA
- Kavli Energy Nano Sciences Institute, University of California Berkeley and Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - Jeffrey B Neaton
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Physics, University of California, Berkeley, CA, USA
| | - Alexander Weber-Bargioni
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Alex Zettl
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Physics, University of California, Berkeley, CA, USA
- Kavli Energy Nano Sciences Institute, University of California Berkeley and Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Z Q Qiu
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Physics, University of California, Berkeley, CA, USA
| | - Guangyu Zhang
- Beijing National Laboratory for Condensed Matter Physics, Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing, China
- Songshan Lake Materials Laboratory, Dongguan, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Feng Wang
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Department of Physics, University of California, Berkeley, CA, USA.
- Kavli Energy Nano Sciences Institute, University of California Berkeley and Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
| | - Joel E Moore
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Department of Physics, University of California, Berkeley, CA, USA.
- Kavli Energy Nano Sciences Institute, University of California Berkeley and Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
| | - Michael F Crommie
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Department of Physics, University of California, Berkeley, CA, USA.
- Kavli Energy Nano Sciences Institute, University of California Berkeley and Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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Zhang C, Zhang J, Liu C, Zhang S, Yuan Y, Li P, Wen Y, Jiang Z, Zhou B, Lei Y, Zheng D, Song C, Hou Z, Mi W, Schwingenschlögl U, Manchon A, Qiu ZQ, Alshareef HN, Peng Y, Zhang XX. Chiral Helimagnetism and One-Dimensional Magnetic Solitons in a Cr-Intercalated Transition Metal Dichalcogenide. Adv Mater 2021; 33:e2101131. [PMID: 34302387 DOI: 10.1002/adma.202101131] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 04/25/2021] [Indexed: 06/13/2023]
Abstract
Chiral magnets endowed with topological spin textures are expected to have promising applications in next-generation magnetic memories. In contrast to the well-studied 2D or 3D magnetic skyrmions, the authors report the discovery of 1D nontrivial magnetic solitons in a transition metal dichalcogenide 2H-TaS2 via precise intercalation of Cr elements. In the synthetic Cr1/3 TaS2 (CTS) single crystal, the coupling of the strong spin-orbit interaction from TaS2 and the chiral arrangement of the magnetic Cr ions evoke a robust Dzyaloshinskii-Moriya interaction. A magnetic helix having a short spatial period of ≈25 nm is observed in CTS via Lorentz transmission electron microscopy. In a magnetic field perpendicular to the helical axis, the helical spin structure transforms into a chiral soliton lattice (CSL) with the spin structure evolution being consistent with the chiral sine-Gordon theory, which opens promising perspectives for the application of CSL to fast-speed nonvolatile magnetic memories. This work introduces a new paradigm to soliton physics and provides an effective strategy for seeking novel 2D magnets.
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Affiliation(s)
- Chenhui Zhang
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Junwei Zhang
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, School of Physical Science and Technology and Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou, Gansu Province, 730000, China
| | - Chen Liu
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Senfu Zhang
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Ye Yuan
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China
| | - Peng Li
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Yan Wen
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Ze Jiang
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, School of Physical Science and Technology and Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou, Gansu Province, 730000, China
| | - Bojian Zhou
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, School of Physical Science and Technology and Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou, Gansu Province, 730000, China
| | - Yongjiu Lei
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Dongxing Zheng
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Chengkun Song
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, School of Physical Science and Technology and Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou, Gansu Province, 730000, China
| | - Zhipeng Hou
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, Guangdong Province, 510006, China
- National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, Guangdong Province, 510006, China
| | - Wenbo Mi
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Processing Technology, Institute of Advanced Materials Physics, Faculty of Science, Tianjin University, Tianjin, Tianjin Municipality, 300354, China
| | - Udo Schwingenschlögl
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | | | - Zi Qiang Qiu
- Department of Physics, University of California, Berkeley, CA, 94720, USA
| | - Husam N Alshareef
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Yong Peng
- Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, School of Physical Science and Technology and Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou, Gansu Province, 730000, China
| | - Xi-Xiang Zhang
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
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9
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Zhou Y, Ma MS, Li GY, Zhang ZJ, Ding J, Xu YW, Qiu ZQ, Song HM. [Analysis of the clinical perinatal characteristics of 226 patients with Prader-Willi syndrome in China]. Zhonghua Er Ke Za Zhi 2021; 59:466-470. [PMID: 34102819 DOI: 10.3760/cma.j.cn112140-20210203-00100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To enhance the early recognition of Prader-Willi syndrome by summarizing the clinical characteristics of Prader-Willi syndrome (PWS) during perinatal period. Methods: Through a nationwide cross-sectional study in the Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences,226 children diagnosed as PWS by molecular genetics were recruited from September 2019 to March 2020. Clinical data including fetuses Age, birth weight, fetal movement, fetal position, amniotic fluid, mode of bith, crying, muscle tension, feeding, and cryptorchidism were collected to analyze the clinical characteristics of Chinese PWS patients in the perinatal period, and according to the mode of birty, birth weight and genotypes to perform subgroup analysis. The clinical manifestations of different subtypes were statistically analyzed by t test, χ2 test or Mann-Whitney U test. Results: Among the 226 PWS patients, 120 were males, and 106 were females. Among them, 100 (44.2%) patients were small for gestational age. Decreased fetal movement was the most common manifestation 202 cases (89.4%) during pregnancy, and other manifestations included polyhydramnios 71 cases (31.4%) and abnormal fetal position 58 cases (25.7%). One hundred and eighty-five (81.9%) patients were delivered by cesarean section and the frequency of abnormal fetal position was significantly higher (30.8%(57/185) vs. 2.4%(1/41),χ²=14.161,P<0.01). As for abnormal manifestations after birth included hypotonia 221 cases (97.8%),220 cases (97.3%) showing weak crying, 116 cases among the total 120 males patients (96.7%) wanifested with cryptordnildism and 206 feeding difficulties (91.2%). In terms of genetic subtype, most of them (184/226, 81.4%) had a paternal deletion, while maternal age (35±5 vs. 29±5, t=-6.591, P<0.01) and the frequency of polyhydramnios (47.6% (20/42) vs. 27.7% (51/185), χ²=6.286, P=0.012) were significantly higher in the non-deletion group. Conclusions: The main manifestations of PWS patients during the perinatal period are hypotonia, weak crying, feeding difficulties, decreased fetal movement, cryptorchidism and those patients are more likely to be born by cesarean section. In newborns with these characteristics, pediatricians should be aware of the possibility of PWS. In terms of the relationship between genotypes and phenotypes, polyhydramnios is more frequently observed in the non-deletion group.
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Affiliation(s)
- Y Zhou
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - M S Ma
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - G Y Li
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Z J Zhang
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - J Ding
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Y W Xu
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - Z Q Qiu
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - H M Song
- Department of Pediatrics, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
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Liu Y, Zang FL, Qiu ZQ, Guo YH, Luo Y, Sun L, Zhao S, Shao B, Liang H, Sun Y. [Association of status of mismatch repair protein expression and EB virus infection with clinicopathological parameters in 886 gastric adenocarcinoma patients]. Zhonghua Wei Chang Wai Ke Za Zhi 2021; 24:440-448. [PMID: 34000774 DOI: 10.3760/cma.j.issn.441530-20200910-00518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To analyze the expression of mismatch repair (MMR) protein and the EB virus infection in gastric adenocarcinoma, and to examine the association of MMR expression and EB virus infection with clinicopathological parameters. Methods: A case-control study was performed. Clinicopathological data of patients who was pathologically diagnosed as gastric adenocarcinoma, received radical gastrectomy and had complete clinicopathological data from August 2017 to April 2020 in Tianjin Medical University Cancer Institute and Hospital were retrospectively collected and analyzed. The immunohistochemistry (IHC) of MMR proteins and in situ hybridization (ISH) of Epstein-Barr virus encoded RNA (EBER) were reviewed. The associations of MMR and EBER results with clinicopathological parameters were analyzed. The main observations of the study were MMR and EBER expression, and association of MMR and EBER results with clinicopathological parameters. Results: Eight hundred and eighty-six patients were enrolled, including 98 patients who received preoperative neoadjuvant chemoradiotherapy. Of 886 patients, 613 (69.2%) were males and the median age was 60 (22-83) years; 831 (93.8%) were mismatch repair proficiency (pMMR), and 55 (6.2%) were mismatch repair deficiency (dMMR). In dMMR group, 47 cases (85.5%) had the deficiency of both MLH1 and PMS2, 1 case (1.8%) had the deficiency of both MSH2 and MSH6, 4 cases (7.3%) had the deficiency only in PMS2, 2 cases (3.6%) had the deficiency only in MSH6, and 1 case (1.8%) had the deficiency only in MSH2. The deficiency rates of PMS2, MLH1, MSH6 and MSH2 were 5.8% (51/886), 5.3% (47/886), 0.3% (3/886) and 0.2% (2/886), respectively. Among the 871 cases with EBER results, 4.9% (43/871) were positive EBER. Univariate analysis showed that dMMR was more frequently detected in female patients (χ(2)=10.962, P=0.001), cancer locating in the antrum (χ(2)=9.336,P=0.020), Lauren intestinal type (χ(2)=9.718, P=0.018), stage T3 (χ(2)=25.866, P<0.001) and TNM stage II (χ(2)=15.470, P=0.002). The ratio of dMMR was not significantly associated with age, tumor differentiation, histological type, lymph node metastasis, distant metastasis or Her-2 immunohistochemical score (all P>0.05). Compared with negative EBER, positive EBER was more frequent in male patients (χ(2)=9.701, P=0.002), cancer locating in gastric fundus and corpus (χ(2)=17.964, P<0.001), gastric cancer with lymphoid stroma (χ(2)=744.073, P<0.001) and poorly differentiated cancer (χ(2)=13.739, P=0.010). Positive EBER was not significantly associated with age, depth of invasion, lymph node metastasis, distant metastasis, TNM stage or Her-2 immunohistochemical score (all P>0.05). In addition, all dMMR cases were EBER negative, and all cases of positive EBER were pMMR. Conclusions: The positive EB virus status is mutually exclusive with dMMR, indicating that different molecular subtypes of gastric adenocarcinoma are involved in different molecular pathways in tumorigenesis and progression. The overlapping of dMMR or positive EBER status and positive Her-2 expression is found in some cases of gastric adenocarcinoma. Patients with gastric adenocarcinoma after radical surgery should be tested for MMR status if they are female, the tumor locates in gastric antrum, the TNM staging is stage II or T3, or if the Lauren classification is intestinal type. And if patients are male, the tumor locates in the gastric fundus and corpus, the cancer is lymphoid stroma, or poor differentiated, the expression of EBER should be detected. Results of our study may provide evidence for further decision-making of clinical treatment.
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Affiliation(s)
- Y Liu
- Department of Pathology, Tianjin Medical University Cancer Institute and Hospital; National Clinical Research Center for Cancer; Key Laboratory of Cancer Prevention and Therapy, Tianjin; Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - F L Zang
- Department of Pathology, Tianjin Medical University Cancer Institute and Hospital; National Clinical Research Center for Cancer; Key Laboratory of Cancer Prevention and Therapy, Tianjin; Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - Z Q Qiu
- Department of Pathology, Tianjin Medical University Cancer Institute and Hospital; National Clinical Research Center for Cancer; Key Laboratory of Cancer Prevention and Therapy, Tianjin; Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - Y H Guo
- Department of Pathology, Tianjin Medical University Cancer Institute and Hospital; National Clinical Research Center for Cancer; Key Laboratory of Cancer Prevention and Therapy, Tianjin; Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - Y Luo
- Department of Pathology, Tianjin Medical University Cancer Institute and Hospital; National Clinical Research Center for Cancer; Key Laboratory of Cancer Prevention and Therapy, Tianjin; Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - L Sun
- Department of Pathology, Tianjin Medical University Cancer Institute and Hospital; National Clinical Research Center for Cancer; Key Laboratory of Cancer Prevention and Therapy, Tianjin; Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - S Zhao
- Department of Pathology, Tianjin Medical University Cancer Institute and Hospital; National Clinical Research Center for Cancer; Key Laboratory of Cancer Prevention and Therapy, Tianjin; Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - B Shao
- Department of Pathology, Tianjin Medical University Cancer Institute and Hospital; National Clinical Research Center for Cancer; Key Laboratory of Cancer Prevention and Therapy, Tianjin; Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - H Liang
- Department of Gastroenterological Surgery, Tianjin Medical University Cancer Institute and Hospital; National Clinical Research Center for Cancer; Key Laboratory of Cancer Prevention and Therapy, Tianjin; Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - Y Sun
- Department of Pathology, Tianjin Medical University Cancer Institute and Hospital; National Clinical Research Center for Cancer; Key Laboratory of Cancer Prevention and Therapy, Tianjin; Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
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11
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Zheng D, Fang YW, Zhang S, Li P, Wen Y, Fang B, He X, Li Y, Zhang C, Tong W, Mi W, Bai H, Alshareef HN, Qiu ZQ, Zhang X. Berry Phase Engineering in SrRuO 3/SrIrO 3/SrTiO 3 Superlattices Induced by Band Structure Reconstruction. ACS Nano 2021; 15:5086-5095. [PMID: 33606942 DOI: 10.1021/acsnano.0c10200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The Berry phase, which reveals the intimate geometrical structure underlying quantum mechanics, plays a central role in the anomalous Hall effect. In this work, we observed a sign change of Berry curvatures at the interface between the ferromagnet SrRuO3 (SRO) layer and the SrIrO3 (SIO) layer with strong spin-orbit coupling. The negative Berry curvature at the interface, induced by the strongly spin-orbit-coupled Ir 5d bands near the Fermi level, makes the SRO/SIO interface different from the SRO layer that has a positive Berry curvature. These opposite Berry curvatures led to two anomalous Hall effect (AHE) channels with opposite signs at the SRO/SIO interface and in the SRO layer, respectively, resulting in a hump-like feature in the Hall resistivity loop. This observation offers a straightforward explanation of the hump-like feature that is usually associated with the chiral magnetic structure or magnetic skyrmions. Hence, this study provides evidence to oppose the widely accepted claim that magnetic skyrmions induce the hump-like feature.
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Affiliation(s)
- Dongxing Zheng
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Processing Technology, Institute of Advanced Materials Physics, Faculty of Science, Tianjin University, Tianjin 300072, China
| | - Yue-Wen Fang
- Laboratory for Materials and Structures & Tokyo Tech World Research Hub Initiative (WRHI), Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
- NYU-ECNU Institute of Physics, New York University Shanghai, Shanghai 200122, China
| | - Senfu Zhang
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Peng Li
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Yan Wen
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Bin Fang
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Xin He
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Yan Li
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Chenhui Zhang
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Wenyi Tong
- Theoretical Materials Physics, Q-MAT, CESAM, Université de Liège, B-4000 Liège, Belgium
| | - Wenbo Mi
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Processing Technology, Institute of Advanced Materials Physics, Faculty of Science, Tianjin University, Tianjin 300072, China
| | - Haili Bai
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Processing Technology, Institute of Advanced Materials Physics, Faculty of Science, Tianjin University, Tianjin 300072, China
| | - Husam N Alshareef
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Zi Qiang Qiu
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, United States
| | - Xixiang Zhang
- Physical Science and Engineering Division (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
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12
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Gweon HK, Lee SY, Kwon HY, Jeong J, Chang HJ, Kim KW, Qiu ZQ, Ryu H, Jang C, Choi JW. Exchange Bias in Weakly Interlayer-Coupled van der Waals Magnet Fe 3GeTe 2. Nano Lett 2021; 21:1672-1678. [PMID: 33570963 DOI: 10.1021/acs.nanolett.0c04434] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
van der Waals (vdW) magnetic materials provide an ideal platform to study low-dimensional magnetism. However, observations of magnetic characteristics of these layered materials truly distinguishing them from conventional magnetic thin film systems have been mostly lacking. In an effort to investigate magnetic properties unique to vdW magnetic materials, we examine the exchange bias effect, a magnetic phenomenon emerging at the ferromagnetic-antiferromagnetic interface. Exchange bias is observed in the naturally oxidized vdW ferromagnet Fe3GeTe2, owing to an antiferromagnetic ordering in the surface oxide layer. Interestingly, the magnitude and thickness dependence of the effect is unlike those expected in typical thin-film systems. We propose a possible mechanism for this behavior, based on the weak interlayer magnetic coupling inherent to vdW magnets, demonstrating the distinct properties of these materials. Furthermore, the robust and sizable exchange bias for vdW magnets persisting up to relatively high temperatures presents a significant advance for realizing practical two-dimensional spintronics.
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Affiliation(s)
- Hyung Keun Gweon
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Sang Yeop Lee
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Hee Young Kwon
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Juyoung Jeong
- Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Hye Jung Chang
- Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
- Division of Nano & Information Technology, KIST school, University of Science and Technology, Seoul 02792, Republic of Korea
| | - Kyoung-Whan Kim
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Zi Qiang Qiu
- Department of Physics, University of California, Berkeley 94720, California, United States
| | - Hyejin Ryu
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Chaun Jang
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Jun Woo Choi
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
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13
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Yang M, Li Q, Chopdekar RV, Dhall R, Turner J, Carlström JD, Ophus C, Klewe C, Shafer P, N'Diaye AT, Choi JW, Chen G, Wu YZ, Hwang C, Wang F, Qiu ZQ. Creation of skyrmions in van der Waals ferromagnet Fe 3GeTe 2 on (Co/Pd) n superlattice. Sci Adv 2020; 6:6/36/eabb5157. [PMID: 32917619 PMCID: PMC7473669 DOI: 10.1126/sciadv.abb5157] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 07/15/2020] [Indexed: 05/27/2023]
Abstract
Magnetic skyrmions are topological spin textures, which usually exist in noncentrosymmetric materials where the crystal inversion symmetry breaking generates the so-called Dzyaloshinskii-Moriya interaction. This requirement unfortunately excludes many important magnetic material classes, including the recently found two-dimensional van der Waals (vdW) magnetic materials, which offer unprecedented opportunities for spintronic technology. Using photoemission electron microscopy and Lorentz transmission electron microscopy, we investigated and stabilized Néel-type magnetic skyrmion in vdW ferromagnetic Fe3GeTe2 on top of (Co/Pd) n in which the Fe3GeTe2 has a centrosymmetric crystal structure. We demonstrate that the magnetic coupling between the Fe3GeTe2 and the (Co/Pd) n could create skyrmions in Fe3GeTe2 without the need of an external magnetic field. Our results open exciting opportunities in spintronic research and the engineering of topologically protected nanoscale features by expanding the group of skyrmion host materials to include these previously unknown vdW magnets.
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Affiliation(s)
- M Yang
- Department of Physics, University of California, Berkeley, CA 94720, USA
| | - Q Li
- Department of Physics, University of California, Berkeley, CA 94720, USA.
| | - R V Chopdekar
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - R Dhall
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - J Turner
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - J D Carlström
- Department of Physics, University of California, Berkeley, CA 94720, USA
| | - C Ophus
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - C Klewe
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - P Shafer
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - A T N'Diaye
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - J W Choi
- Center for Spintronics, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - G Chen
- Department of Physics, University of California, Davis, CA 95616, USA
| | - Y Z Wu
- Department of Physics and State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433, China
| | - C Hwang
- Korea Research Institute of Standards and Science, Yuseong, Daejeon 305-340, Republic of Korea
| | - F Wang
- Department of Physics, University of California, Berkeley, CA 94720, USA
| | - Z Q Qiu
- Department of Physics, University of California, Berkeley, CA 94720, USA.
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14
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Prasad B, Huang YL, Chopdekar RV, Chen Z, Steffes J, Das S, Li Q, Yang M, Lin CC, Gosavi T, Nikonov DE, Qiu ZQ, Martin LW, Huey BD, Young I, Íñiguez J, Manipatruni S, Ramesh R. Ultralow Voltage Manipulation of Ferromagnetism. Adv Mater 2020; 32:e2001943. [PMID: 32468701 DOI: 10.1002/adma.202001943] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 04/27/2020] [Accepted: 04/28/2020] [Indexed: 06/11/2023]
Abstract
Spintronic elements based on spin transfer torque have emerged with potential for on-chip memory, but they suffer from large energy dissipation due to the large current densities required. In contrast, an electric-field-driven magneto-electric storage element can operate with capacitive displacement charge and potentially reach 1-10 µJ cm-2 switching operation. Here, magneto-electric switching of a magnetoresistive element is shown, operating at or below 200 mV, with a pathway to get down to 100 mV. A combination of phase detuning is utilized via isovalent La substitution and thickness scaling in multiferroic BiFeO3 to scale the switching energy density to ≈10 µJ cm-2 . This work provides a template to achieve attojoule-class nonvolatile memories.
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Affiliation(s)
- Bhagwati Prasad
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - Yen-Lin Huang
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley Laboratory, Berkeley, CA, 94720, USA
| | - Rajesh V Chopdekar
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Zuhuang Chen
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - James Steffes
- Institute of Materials Science, University of Connecticut, Storrs, CT, 06269, USA
| | - Sujit Das
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - Qian Li
- Department of Physics, University of California, Berkeley, CA, 94720, USA
| | - Mengmeng Yang
- Department of Physics, University of California, Berkeley, CA, 94720, USA
| | - Chia-Ching Lin
- Exploratory Integrated Circuits, Components Research, Intel Corp., Hillsboro, OR, 97124, USA
| | - Tanay Gosavi
- Exploratory Integrated Circuits, Components Research, Intel Corp., Hillsboro, OR, 97124, USA
| | - Dmitri E Nikonov
- Exploratory Integrated Circuits, Components Research, Intel Corp., Hillsboro, OR, 97124, USA
| | - Zi Qiang Qiu
- Department of Physics, University of California, Berkeley, CA, 94720, USA
| | - Lane W Martin
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley Laboratory, Berkeley, CA, 94720, USA
| | - Bryan D Huey
- Institute of Materials Science, University of Connecticut, Storrs, CT, 06269, USA
| | - Ian Young
- Exploratory Integrated Circuits, Components Research, Intel Corp., Hillsboro, OR, 97124, USA
| | - Jorge Íñiguez
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST), Avenue des Hauts-Fourneaux 5, Esch-sur-Alzette, L-4362, Luxemburg
- Physics and Materials Science Research Unit, University of Luxembourg, 41 Rue du Brill, Belvaux, L-4422, Luxembourg
| | - Sasikanth Manipatruni
- Exploratory Integrated Circuits, Components Research, Intel Corp., Hillsboro, OR, 97124, USA
- Kepler Computing, Hillsboro, OR, 97124, USA
| | - Ramamoorthy Ramesh
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
- Department of Physics, University of California, Berkeley, CA, 94720, USA
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15
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Gao N, Je SG, Im MY, Choi JW, Yang M, Li Q, Wang TY, Lee S, Han HS, Lee KS, Chao W, Hwang C, Li J, Qiu ZQ. Creation and annihilation of topological meron pairs in in-plane magnetized films. Nat Commun 2019; 10:5603. [PMID: 31811144 PMCID: PMC6898613 DOI: 10.1038/s41467-019-13642-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 11/18/2019] [Indexed: 11/10/2022] Open
Abstract
Merons which are topologically equivalent to one-half of skyrmions can exist only in pairs or groups in two-dimensional (2D) ferromagnetic (FM) systems. The recent discovery of meron lattice in chiral magnet Co8Zn9Mn3 raises the immediate challenging question that whether a single meron pair, which is the most fundamental topological structure in any 2D meron systems, can be created and stabilized in a continuous FM film? Utilizing winding number conservation, we develop a new method to create and stabilize a single pair of merons in a continuous Py film by local vortex imprinting from a Co disk. By observing the created meron pair directly within a magnetic field, we determine its topological structure unambiguously and explore the topological effect in its creation and annihilation processes. Our work opens a pathway towards developing and controlling topological structures in general magnetic systems without the restriction of perpendicular anisotropy and Dzyaloshinskii–Moriya interaction. A meron is one half of a skyrmion but whether a single meron pair can be created and stabilized remains a challenging question. Here, Gao et al. develop a method to create and stabilize individual pairs of merons in a continuous Py film by local vortex imprinting from Co disks.
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Affiliation(s)
- N Gao
- Key Laboratory of Microelectronic Devices and Integrated Technology, Institute of Microelectronics of Chinese Academy of Sciences, Beijing, 100029, China.,Department of Physics, University of California at Berkeley, Berkeley, CA, 94720, USA
| | - S -G Je
- Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - M -Y Im
- Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,Department of Emerging Materials Science, DGIST, Daegu, Korea
| | - J W Choi
- Center for Spintronics, Korea Institute of Science and Technology, Seoul, 02792, Korea
| | - M Yang
- Department of Physics, University of California at Berkeley, Berkeley, CA, 94720, USA
| | - Q Li
- Department of Physics, University of California at Berkeley, Berkeley, CA, 94720, USA
| | - T Y Wang
- Department of Physics, University of California at Berkeley, Berkeley, CA, 94720, USA
| | - S Lee
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, Korea
| | - H -S Han
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, Korea
| | - K -S Lee
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, Korea
| | - W Chao
- Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - C Hwang
- Korea Research Institute of Standards and Science, Yuseong, Daejeon, 305-340, Korea
| | - J Li
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China.
| | - Z Q Qiu
- Department of Physics, University of California at Berkeley, Berkeley, CA, 94720, USA.
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16
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Xu N, Huang XM, Fang WG, Zhang Y, Qiu ZQ, Zeng XJ. [Glycogen storage disease type Ⅰa: a rare cause of gout in adolescent and young adult patients]. Zhonghua Nei Ke Za Zhi 2018; 57:264-269. [PMID: 29614584 DOI: 10.3760/cma.j.issn.0578-1426.2018.04.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To analyze the clinical features of secondary gout in glycogen storage disease type Ⅰa (GSD Ⅰa), so as to improve the awareness of this disease. Methods: The clinical features, laboratory findings, treatments and prognosis of 5 GSD Ⅰa patients with secondary gout who had been admitted to the Peking Union Medical College Hospital during 2006 to 2016 were collected and analyzed. GSD Ⅰa was confirmed by liver biopsy and genotyping. Results: Among the 5 patients (median age: 27 years), 3 were males and 2 were females. The mean age of gout onset was 17 ranging from 10 to 22 years old. The common manifestations of GSD included hepatomegaly since childhood, hypoglycemia, growth retardation, anemia, hyperlactacidemia and hyperlipidemia. All the 5 patients were complicated with gouty tophi and kidney stone. Gouty tophi and kidney stone were identified 3.8 years and 10.2 years after the first occurrence of articular symptoms, respectively. Renal damage occurred in 3 cases. All the patients underwent several therapeutic modalities including lifestyle intervention, allopurinol, and raw corn starch treatment. Conclusions: Determination of the presence of primary disease should be performed actively for young-onset gout with early occurrence of gouty tophi. GSD should be suspected if there exist clinical manifestations like hepatomegaly, recurrent hypoglycemia, growth retardation. Early management of hyperuricemia and gout in GSD patients is important to prevent complications and improve prognosis.
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Affiliation(s)
| | | | | | | | | | - X J Zeng
- Department of General Internal Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
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17
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Zheng CF, Zeng H, Wang J, Lin H, Feng XB, Chen JA, Qiu ZQ, Luo JH, Xu AW, Wang LQ, Tan Y, Chen S, Jiang P, Shu WQ. [The association between aflatoxin exposure and primary hepatocellular carcinoma risks: a case-control study in Chongqing]. Zhonghua Yu Fang Yi Xue Za Zhi 2017; 51:539-545. [PMID: 28592100 DOI: 10.3760/cma.j.issn.0253-9624.2017.06.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To investigate the association between aflatoxin exposure and primary hepatocellular carcinoma (PHC) development. Methods: From December 2013 to May 2016, we selected 214 patients newly diagnosed with PHC as cases, and 214 patients as controls from three hospitals in Chongqing. Cases were confirmed with PHC diagnosis standard. And cases caused by clear reasons such as drug-induced liver injury, alcoholic liver damage, fatty liver and gallstones etiology, were excluded. Controls were included with no cancer and no digestive system disease, and recruited simultaneously with cases. Cases and controls were frequency-matched (1∶1) by same gender and age (±3 years). Peripheral blood and random urine samples were collected and analyzed for serum HBsAg status by biochemistry analyzer, and serum AFB(1)-ALB adduct and urinary AFB(1)-N(7)-GUA adduct by ELISA. Basic information, living habits and history of disease for patients were obtained by questionnaires. We used wilcoxon rank sum test to compare the median of serum AFB(1)-ALB adduct and urinary AFB(1)-N(7)-GUA adduct in cases and controls. Logistic regression analyses were performed to assess risk factors for PHC, and synergism index (S) of aflatoxin with other factors was estimated by the method of Andersson. Results: There was no significant difference in age between PHC cases (50.74±9.67) years and controls (51.15±9.90) years. Logistic regression showed that the odds ratio of HBV infection for PHC development was 46.3 (95% CI: 23.3-88.0). There was a significant difference in median concentrations of serum AFB(1)-ALB adduct (cases vs controls: 146.23 vs 74.42 ng/g albumin, P<0.001), but no difference in median concentrations of urinary AFB(1)-N(7)-GUA adduct was observed (cases vs controls: 0.17 vs 0.14 ng/mg creatinine, P<0.210). The odd ratios for PHC risk after adjustment were 1.9 (95%CI: 1.1-3.4) for AFB(1)-ALB adduct, and 2.1 (95%CI: 1.0-4.2) for AFB(1)-N(7)-GUA adduct. Moreover, we observed a positive interaction of aflatoxin exposure with HBV, alcohol drinking, and diabetes. The S was 4.7 (95%CI: 2.8-7.9), 3.5 (95%CI: 1.0-12.0), and 12.4 (95%CI: 1.8-84.2), respectively for serum AFB(1)-ALB adduct with each of the three factors mentioned, and was 1.9 (95%CI:1.1-3.1), 2.0 (95%CI: 1.1-3.6), and 2.0 (95%CI: 1.1-3.6), respectively for urinary AFB(1)-N(7)-GUA adduct with each of the three factors mentioned. Conclusion: HBV was still the main risk factor, and AFB(1) exposure was also an independent risk factor for PHC in Chongqing. There was a positive interaction of aflatoxin with HBV, alcohol drinking, and diabetes.
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Affiliation(s)
- C F Zheng
- Department of Environmental Hygiene, College of Preventive Medicine, Third Military Medical University, Chongqing 400038, China
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Wu WC, Wang W, Song HM, Ma MS, Tang XY, Jian S, Zhang MQ, Xiao J, Qiu ZQ, Liu YL. [A major histocompatibility complex class Ⅱ deficiency case report and literature review]. Zhonghua Er Ke Za Zhi 2017; 54:614-8. [PMID: 27510876 DOI: 10.3760/cma.j.issn.0578-1310.2016.08.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVE To summarize and report the clinical characteristics and laboratory results of a case and those reported in literature with MHC class Ⅱ deficiency. METHOD The clinical features, laboratory results and gene mutation analysis of an infant with MHC class Ⅱ deficiency, who was diagnosed and treated in Peking Union Medical College Hospital since December 2013, were retrospectively analyzed."Major histocompatibility complex class Ⅱ deficiency"or"bare lymphocyte syndrome"were used as keywords in order to retrieve reports from CNKI (from its establishment to October 2015) and Wanfang Database (from its establishment to October 2015), PubMed Database (from its establishment to October 2015) was searched. The characteristics, diagnosis, treatment and prognosis were summarized by reviewing related articles. RESULT The patient was a 8-month-old boy. Since the fourth month of life, he started to have repeated fever, susceptible to a variety of pathogens, immune hemolytic anemia, severe malnutrition, and finally diagnosed as MHC class Ⅱ deficiency disease when he was 20-month-old.No related reports were retrieved from CNKI and Wanfang database, there were 20 articles and 179 patients were reported worldwide in the past 10 years. Patients exhibit an extreme vulnerability to infections(resptratory infection(82%, 146/178), inpection of gastroin testinal(76%, 135/178)). The common laboratory examinations showed hypogammaglobulinemia, CD4(+) lymphopenia(93%, 107/115) etc. Diagnosis relies on the flow-cytometric analysis and genetic analysis. CONCLUSION It is considered necessary for patients with young onset age, manifestation of clinically opportunistic infection as immune deficient disease, including the MHC class Ⅱ deficiency disease, especially long-term diarrhea, poor development and cryptosporidium infection. This disease could coexist with autoimmune disorders.
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Affiliation(s)
- W C Wu
- Department of Pediatrics, Chinese Academy of Medical Sciences, Peking Union Medical College Hospital, Beijing 100730, China
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Li J, Shelford LR, Shafer P, Tan A, Deng JX, Keatley PS, Hwang C, Arenholz E, van der Laan G, Hicken RJ, Qiu ZQ. Direct Detection of Pure ac Spin Current by X-Ray Pump-Probe Measurements. Phys Rev Lett 2016; 117:076602. [PMID: 27563981 DOI: 10.1103/physrevlett.117.076602] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Indexed: 06/06/2023]
Abstract
Despite recent progress in spin-current research, the detection of spin current has mostly remained indirect. By synchronizing a microwave waveform with synchrotron x-ray pulses, we use the ferromagnetic resonance of the Py (Ni_{81}Fe_{19}) layer in a Py/Cu/Cu_{75}Mn_{25}/Cu/Co multilayer to pump a pure ac spin current into the Cu_{75}Mn_{25} and Co layers, and then directly probe the spin current within the Cu_{75}Mn_{25} layer and the spin dynamics of the Co layer by x-ray magnetic circular dichroism. This element-resolved pump-probe measurement unambiguously identifies the ac spin current in the Cu_{75}Mn_{25} layer.
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Affiliation(s)
- J Li
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA
| | - L R Shelford
- Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter, Devon EX4 4QL, United Kingdom
| | - P Shafer
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - A Tan
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA
| | - J X Deng
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA
| | - P S Keatley
- Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter, Devon EX4 4QL, United Kingdom
| | - C Hwang
- Korea Research Institute of Standards and Science, Yuseong, Daejeon 305-340, Republic of Korea
| | - E Arenholz
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - G van der Laan
- Magnetic Spectroscopy Group, Diamond Light Source, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - R J Hicken
- Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter, Devon EX4 4QL, United Kingdom
| | - Z Q Qiu
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA
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20
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Ma S, Tan A, Deng JX, Li J, Zhang ZD, Hwang C, Qiu ZQ. Tailoring the magnetic anisotropy of Py/Ni bilayer films using well aligned atomic steps on Cu(001). Sci Rep 2015; 5:11055. [PMID: 26067408 PMCID: PMC4464147 DOI: 10.1038/srep11055] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 05/11/2015] [Indexed: 11/09/2022] Open
Abstract
Tailoring the spin orientation at the atomic scale has been a key task in spintronics technology. While controlling the out-of-plane to in-plane spin orientation has been achieved by a precise control of the perpendicular magnetic anisotropy at atomic layer thickness level, a design and control of the in-plane magnetic anisotropy has not yet been well developed. On well aligned atomic steps of a 6° vicinal Cu(001) surface with steps parallel to the [110] axis, we grow Py/Ni overlayer films epitaxially to permit a systematic exploration of the step-induced in-plane magnetic anisotropy as a function of both the Py and the Ni film thicknesses. We found that the atomic steps from the vicinal Cu(001) induce an in-plane uniaxial magnetic anisotropy that favors both Py and Ni magnetizations perpendicular to the steps, opposite to the behavior of Co on vicinal Cu(001). In addition, thickness-dependent study shows that the Ni films exhibit different magnetic anisotropy below and above ~6 ML Ni thickness.
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Affiliation(s)
- S Ma
- 1] Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China [2] Department of Physics, University of California at Berkeley, Berkeley,California 94720
| | - A Tan
- Department of Physics, University of California at Berkeley, Berkeley,California 94720
| | - J X Deng
- Department of Physics, University of California at Berkeley, Berkeley,California 94720
| | - J Li
- Department of Physics, University of California at Berkeley, Berkeley,California 94720
| | - Z D Zhang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - C Hwang
- Korea Research Institute of Standards and Science, Yuseong, Daejeon 305-340, Korea
| | - Z Q Qiu
- Department of Physics, University of California at Berkeley, Berkeley,California 94720
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21
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Li J, Tan A, Ma S, Yang RF, Arenholz E, Hwang C, Qiu ZQ. Chirality switching and winding or unwinding of the antiferromagnetic NiO domain walls in Fe/NiO/Fe/CoO/Ag(001). Phys Rev Lett 2014; 113:147207. [PMID: 25325659 DOI: 10.1103/physrevlett.113.147207] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Indexed: 06/04/2023]
Abstract
Fe/NiO/Fe/CoO/Ag(001) single crystalline films were grown epitaxially and investigated by x-ray magnetic circular dichroism and x-ray magnetic linear dichroism. The bottom Fe layer magnetization is pinned through exchange coupling to the CoO layer and the top Fe layer magnetization can be rotated by an in-plane external magnetic field. We find that the NiO spins wind up to form a domain wall due to the perpendicular NiO/Fe interfacial coupling as the top layer Fe magnetization rotates from 0° to 90°, but switch wall chirality and unwind the wall as the Fe magnetization rotates from 90° to 180°. This observation shows that Mauri's 180° domain wall does not exist in perpendicularly coupled ferromagnetic-antiferromagnetic systems in the strong coupling regime.
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Affiliation(s)
- J Li
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA
| | - A Tan
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA
| | - S Ma
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA and Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - R F Yang
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA
| | - E Arenholz
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - C Hwang
- Korea Research Institute of Standards and Science, Yuseong, Daejeon 305-340, Korea
| | - Z Q Qiu
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA
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22
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Chen G, Zhu J, Quesada A, Li J, N'Diaye AT, Huo Y, Ma TP, Chen Y, Kwon HY, Won C, Qiu ZQ, Schmid AK, Wu YZ. Novel chiral magnetic domain wall structure in Fe/Ni/Cu(001) films. Phys Rev Lett 2013; 110:177204. [PMID: 23679766 DOI: 10.1103/physrevlett.110.177204] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Indexed: 06/02/2023]
Abstract
Using spin-polarized low energy electron microscopy, we discovered a new type of domain wall structure in perpendicularly magnetized Fe/Ni bilayers grown epitaxially on Cu(100). Specifically, we observed unexpected Néel-type walls with fixed chirality in the magnetic stripe phase. Furthermore, we find that the chirality of the domain walls is determined by the film growth order with the chirality being right handed in Fe/Ni bilayers and left handed in Ni/Fe bilayers, suggesting that the underlying mechanism is the Dzyaloshinskii-Moriya interaction at the film interfaces. Our observations may open a new route to control chiral spin structures using interfacial engineering in transition metal heterostructures.
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Affiliation(s)
- G Chen
- Department of Physics, State Key Laboratory of Surface Physics, Center for Spintronic Devices and Applications, Fudan University, Shanghai 200433, People's Republic of China
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Li J, Jin E, Son H, Tan A, Cao WN, Hwang C, Qiu ZQ. Design of a vector magnet for the measurements of anisotropic magnetoresistance and rotational magneto-optic Kerr effect. Rev Sci Instrum 2012; 83:033906. [PMID: 22462937 DOI: 10.1063/1.3698297] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A vector magnet is designed and assembled with two electromagnets to produce a rotational magnetic field in any direction within a plane. This design allows a rotation of the magnetic field without a mechanical rotation of the magnets. The fast speed of the field rotation (~10 s for a complete 360° rotation) and the stability against mechanical vibration easily overcome the slow drifting effect in anisotropic magnetoresistance (AMR) and rotational magneto-optic Kerr effect (ROTMOKE) measurements. As an example we applied this vector magnet to carry out AMR and ROTMOKE measurements on epitaxial growth of Fe(10 nm)∕MgO(001) films. The result demonstrates the stability and high quality of the vector magnet in determining the magnetic anisotropy of magnetic thin films using AMR and ROTMOKE techniques.
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Affiliation(s)
- J Li
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA
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24
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Wu J, Carlton D, Oelker E, Park JS, Jin E, Arenholz E, Scholl A, Hwang C, Bokor J, Qiu ZQ. Switching a magnetic vortex by interlayer coupling in epitaxially grown Co/Cu/Py/Cu(001) trilayer disks. J Phys Condens Matter 2010; 22:342001. [PMID: 21403243 DOI: 10.1088/0953-8984/22/34/342001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Epitaxial Py/Cu/Co/Cu(001) trilayers were patterned into micron sized disks and imaged using element-specific photoemission electron microscopy. By varying the Cu spacer layer thickness, we study how the coupling between the two magnetic layers influences the formation of magnetic vortex states. We find that while the Py and Co disks form magnetic vortex domains when the interlayer coupling is ferromagnetic, the magnetic vortex domains of the Py and Co disks break into anti-parallel aligned multidomains when the interlayer coupling is antiferromagnetic. We explain this result in terms of magnetic flux closure between the Py and Co layers for the antiferromagnetic coupling case.
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Affiliation(s)
- J Wu
- Department of Physics, University of California at Berkeley, Berkeley, CA 94720, USA
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25
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Wu J, Park JS, Kim W, Arenholz E, Liberati M, Scholl A, Wu YZ, Hwang C, Qiu ZQ. Direct measurement of rotatable and frozen CoO spins in exchange bias system of CoO/Fe/Ag(001). Phys Rev Lett 2010; 104:217204. [PMID: 20867133 DOI: 10.1103/physrevlett.104.217204] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Indexed: 05/29/2023]
Abstract
The exchange bias of epitaxially grown CoO/Fe/Ag(001) was investigated using x-ray magnetic circular dichroism and x-ray magnetic linear dichroism (XMLD) techniques. A direct XMLD measurement on the CoO layer during the Fe magnetization reversal shows that the CoO compensated spins are rotatable at thinner thickness and frozen at larger thickness. By a quantitative determination of the rotatable and frozen CoO spins as a function of the CoO film thickness, we find the remarkable result that the exchange bias is well established before frozen spins are detectable in the CoO film. We further show that the rotatable and frozen CoO spins are uniformly distributed in the CoO film.
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Affiliation(s)
- J Wu
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA
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26
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Won C, Wu YZ, Arenholz E, Choi J, Wu J, Qiu ZQ. Symmetry-breaking induced exchange bias in ferromagnetic Ni-Cu-Co and Ni-Fe-Co sandwiches grown on a vicinal Cu(001) surface. Phys Rev Lett 2007; 99:077203. [PMID: 17930921 DOI: 10.1103/physrevlett.99.077203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2007] [Indexed: 05/25/2023]
Abstract
Ferromagnetic Ni-Cu-Co and Ni-Fe-Co sandwiches were grown epitaxially onto a vicinal Cu(001) substrate and investigated using magneto-optical Kerr effect and x-ray magnetic circular dichroism techniques. We find that the atomic steps of the vicinal surface break the magnetic reversal symmetry to induce an exchange bias in the Ni perpendicular magnetic hysteresis loop. The Ni exchange bias direction can be switched by changing the direction of the in-plane Co magnetization. In addition, the exchange bias can be tailored by changing the Cu or Fe spacer layer thickness.
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Affiliation(s)
- C Won
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA
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27
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Choi J, Wu J, Won C, Wu YZ, Scholl A, Doran A, Owens T, Qiu ZQ. Magnetic bubble domain phase at the spin reorientation transition of ultrathin Fe/Ni/Cu(001) film. Phys Rev Lett 2007; 98:207205. [PMID: 17677736 DOI: 10.1103/physrevlett.98.207205] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2006] [Revised: 03/01/2007] [Indexed: 05/16/2023]
Abstract
Magnetic domain phases of ultrathin Fe/Ni/Cu(001) are studied using photoemission electron microscopy at the spin reorientation transition (SRT). We observe a new magnetic phase of bubble domains within a narrow SRT region after applying a nearly in-plane magnetic field pulse to the sample. By applying the magnetic field pulse along different directions, we find that the bubble domain phase exists only if the magnetic field direction is less than approximately 10 degrees relative to the sample surface. A temperature dependent measurement shows that the bubble domain phase becomes unstable above 370 K.
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Affiliation(s)
- J Choi
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA
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28
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Wu YZ, Schmid AK, Qiu ZQ. Spin-dependent quantum interference from epitaxial MgO thin films on Fe(001). Phys Rev Lett 2006; 97:217205. [PMID: 17155772 DOI: 10.1103/physrevlett.97.217205] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2006] [Indexed: 05/12/2023]
Abstract
Spin-dependent electron reflection from MgO thin films grown on Fe(001) was measured using spin-polarized low energy electron microscopy. The electron reflectivity exhibits quantum interference from which two MgO energy bands with Delta1 symmetry were determined in experiment. We found that a bulklike MgO energy gap is fully established for MgO film thicker than 3 atomic monolayers and that the electron reflectivity from the MgO/Fe interface exhibits a spin-dependent amplitude and a spin-independent phase change.
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Affiliation(s)
- Y Z Wu
- Surface Physics Laboratory (National Key Laboratory), Fudan University, Shanghai 200433, China.
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29
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Zhang YF, Jia JF, Han TZ, Tang Z, Shen QT, Guo Y, Qiu ZQ, Xue QK. Band structure and oscillatory electron-phonon coupling of Pb thin films determined by atomic-layer-resolved quantum-well states. Phys Rev Lett 2005; 95:096802. [PMID: 16197236 DOI: 10.1103/physrevlett.95.096802] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2004] [Indexed: 05/04/2023]
Abstract
Using a low temperature growth method, we have prepared atomically flat Pb thin films over a wide range of film thickness on a Si-(111)-7 x 7 surface. The Pb film morphology and electronic structure are investigated in situ by scanning tunneling microscopy and angle-resolved photoemission spectroscopy. Well-defined and atomic-layer-resolved quantum-well states of the Pb films are used to determine the band structure and the electron-phonon coupling constant (lambda) of the films. We found an oscillatory behavior of lambda with an oscillation periodicity of two atomic layers. Almost all essential features in the Pb/Si(111) system, such as the growth mode, the oscillatory film stability, and the 9 monolayer envelope beating pattern, can be explained by our results in terms of the electron confinement in Pb films.
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Affiliation(s)
- Yan-Feng Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, The Chinese Academy of Sciences, Beijing 100080, China
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Tian CS, Qian D, Wu D, He RH, Wu YZ, Tang WX, Yin LF, Shi YS, Dong GS, Jin XF, Jiang XM, Liu FQ, Qian HJ, Sun K, Wang LM, Rossi G, Qiu ZQ, Shi J. Body-centered-cubic Ni and its magnetic properties. Phys Rev Lett 2005; 94:137210. [PMID: 15904031 DOI: 10.1103/physrevlett.94.137210] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2004] [Indexed: 05/02/2023]
Abstract
The body-centered-cubic (bcc) phase of Ni, which does not exist in nature, has been achieved as a thin film on GaAs(001) at 170 K via molecular beam epitaxy. The bcc Ni is ferromagnetic with a Curie temperature of 456 K and possesses a magnetic moment of 0.52+/-0.08 micro(B)/atom. The cubic magnetocrystalline anisotropy of bcc Ni is determined to be +4.0x10(5) ergs x cm(-3), as opposed to -5.7x10(4) ergs x cm(-3) for the naturally occurring face-centered-cubic (fcc) Ni. This sharp contrast in the magnetic anisotropy is attributed to the different electronic band structures between bcc Ni and fcc Ni, which are determined using angle-resolved photoemission with synchrotron radiation.
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Affiliation(s)
- C S Tian
- Surface Physics Laboratory, Fudan University, Shanghai 200433, China
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31
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Wu YZ, Schmid AK, Altman MS, Jin XF, Qiu ZQ. Spin-dependent Fabry-Pérot interference from a Cu thin film grown on fcc Co(001). Phys Rev Lett 2005; 94:027201. [PMID: 15698221 DOI: 10.1103/physrevlett.94.027201] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2004] [Indexed: 05/24/2023]
Abstract
Spin-dependent electron reflection from a Cu thin film grown on Co/Cu(001) was investigated using spin-polarized low-energy electron microscopy (SPLEEM). Fabry-Pe rot type interference was observed and is explained using the phase accumulation model. SPLEEM images of the Cu overlayer reveal magnetic domains in the Co underlayer, with the domain contrast oscillating with electron energy and Cu film thickness. This behavior is attributed to the spin-dependent electron reflectivity at the Cu/Co interface which leads to spin-dependent Fabry-Pe rot electron interference in the Cu film.
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Affiliation(s)
- Y Z Wu
- Department of Physics, University of California, Berkeley, California 94720, USA
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32
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Guo Y, Zhang YF, Bao XY, Han TZ, Tang Z, Zhang LX, Zhu WG, Wang EG, Niu Q, Qiu ZQ, Jia JF, Zhao ZX, Xue QK. Superconductivity Modulated by Quantum Size Effects. Science 2004; 306:1915-7. [PMID: 15591197 DOI: 10.1126/science.1105130] [Citation(s) in RCA: 498] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We have fabricated ultrathin lead films on silicon substrates with atomic-scale control of the thickness over a macroscopic area. We observed oscillatory behavior of the superconducting transition temperature when the film thickness was increased by one atomic layer at a time. This oscillating behavior was shown to be a manifestation of the Fabry-Perot interference modes of electron de Broglie waves (quantum well states) in the films, which modulate the electron density of states near the Fermi level and the electron-phonon coupling, which are the two factors that control superconductivity transitions. This result suggests the possibility of modifying superconductivity and other physical properties of a thin film by exploiting well-controlled and thickness-dependent quantum size effects.
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Affiliation(s)
- Yang Guo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
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Abstract
Quantum well (QW) resonances are identified in Ag films on an Fe(100) surface and are used in low energy electron microscopy to monitor film morphology during annealing and growth. We find that Ag films thermally decompose to thicknesses that are stabilized by QW states at the Gamma point. Novel growth morphologies are also observed that highlight the competition between kinetic limitations and the QW state energetics that promote electronic growth. These combined observations help to explain the unusual bifurcation mode of thermal decomposition that was reported previously for this system.
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Affiliation(s)
- K L Man
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
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Wu YZ, Won C, Scholl A, Doran A, Zhao HW, Jin XF, Qiu ZQ. Magnetic stripe domains in coupled magnetic sandwiches. Phys Rev Lett 2004; 93:117205. [PMID: 15447377 DOI: 10.1103/physrevlett.93.117205] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2004] [Indexed: 05/24/2023]
Abstract
Magnetic stripe domains in the spin reorientation transition region are investigated in (Fe/Ni)/Cu(001) and Co/Cu/(Fe/Ni)/Cu(001) using photoemission electron microscopy. For (Fe/Ni)/Cu(001), the stripe domain width decreases exponentially as the Fe/Ni film approaches the spin reorientation transition point. For Co/Cu/(Fe/Ni)/Cu(001), the Fe/Ni stripe orientation is aligned with the Co in-plane magnetization, and the stripe domain width decreases exponentially with increasing the interlayer coupling between the Fe/Ni and Co films. By considering magnetic stripes within an in-plane magnetic field, we reveal a universal dependence of the stripe domain width on the magnetic anisotropy and on the interlayer coupling.
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Affiliation(s)
- Y Z Wu
- Department of Physics, University of California Berkeley, Berkeley California 94720, USA
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Abstract
X-linked hypophosphatemia (XLH) is characterized by rickets and osteomalacia and arises from mutations in the Phex and PHEX genes in mice (Hyp) and humans, respectively. The present study was undertaken to examine the effect of gene dose on the skeletal phenotype using a histomorphometric approach. Metrical traits (vertebral length, growth plate thickness, cancellous osteoid volume per bone volume, and cancellous, endocortical, and periosteal osteoid thickness) were compared in caudal vertebrae of mutant female (Hyp/+, Hyp/Hyp) and male (Hyp/Y) mice and their normal female (+/+) and male (+/Y) littermates. Mutant animals had trait values that differed significantly from those of normal animals. However, with the exception of vertebral length and cancellous osteoid thickness, values were not significantly different between the three mutant genotypes. We also examined the effect of gamete-of-origin on histomorphometric parameters in obligate Hyp/+ females derived from male or female transmitting parents. The metrical trait values in both groups of Hyp/+ mice were similar, with the exception of vertebral length and cancellous osteoid volume per bone volume. In summary, we demonstrate that the amount of osteoid per bone volume is similar in the three mutant genotypes and conclude that the extent and magnitude of the mineralization defect is fully dominant and likely not affected by gene dose. The differences in vertebral length in the mutants suggest that rickets and osteomalacia are not the only causes of decreased vertebral growth in Hyp mice and that Phex protein may influence bone growth and mineralization by distinct pathways.
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Affiliation(s)
- Z Q Qiu
- Department of Biology, McGill University, Montreal, Quebec H3A 1B1, Canada
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Won C, Wu YZ, Scholl A, Doran A, Kurahashi N, Zhao HW, Qiu ZQ. Magnetic phase transition in Co/Cu/Ni/Cu(100) and Co/Fe/Ni/Cu(100). Phys Rev Lett 2003; 91:147202. [PMID: 14611550 DOI: 10.1103/physrevlett.91.147202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2002] [Revised: 07/10/2003] [Indexed: 05/24/2023]
Abstract
Magnetic phase transitions in coupled magnetic sandwiches of Cu/Co/Cu/Ni/Cu(100) and Cu/Co/Fe/Ni/Cu(100) are investigated by photoemission electron microscopy. Element-specific magnetic domains are taken at room temperature to reveal the critical thickness at which the magnetic phase transition occurs. The results show that a coupled magnetic sandwich undergoes three types of magnetic phase transitions depending on the two ferromagnetic films' thickness. A phase diagram is constructed and explained in the process of constructing Monte Carlo simulations, which corroborate the experimental results.
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Affiliation(s)
- C Won
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA
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Kawakami RK, Escorcia-Aparicio EJ, Qiu ZQ. Symmetry-Induced Magnetic Anisotropy in Fe Films Grown on Stepped Ag(001). Phys Rev Lett 1996; 77:2570-2573. [PMID: 10061987 DOI: 10.1103/physrevlett.77.2570] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Escorcia-Aparicio EJ, Kawakami RK, Qiu ZQ. fcc Fe films grown on a ferromagnetic fcc Co(100) substrate. Phys Rev B Condens Matter 1996; 54:4155-4158. [PMID: 9986318 DOI: 10.1103/physrevb.54.4155] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Li D, Freitag M, Pearson J, Qiu ZQ, Bader SD. Magnetic phases of ultrathin Fe grown on Cu(100) as epitaxial wedges. Phys Rev Lett 1994; 72:3112-3115. [PMID: 10056070 DOI: 10.1103/physrevlett.72.3112] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Qiu ZQ, Pearson J, Bader SD. Two-dimensional Ising transition of epitaxial Fe films grown on Ag(100). Phys Rev B Condens Matter 1994; 49:8797-8801. [PMID: 10009661 DOI: 10.1103/physrevb.49.8797] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Abstract
The expectation for a gene dose effect in an X-linked phenotype is that the corresponding metrical trait in heterozygous females will lie between values for affected hemizygous males and unaffected males and females. We made sequential measurements (at 30, 60, 90, 120 and 150 days) of serum phosphate concentration and tail length in mice with X-linked hypophosphatemia (genotypes: Hyp/Y, Hyp/+ and Hyp/Hyp) and in their normal litter-mates (genotypes: +/Y, +/+). We also measured renal mitochondrial 25-hydroxyvitamin D3-24-hydroxylase (24-hydroxylase) activity in 5 to 7-month-old mice fed control and low phosphate diets and representing all five genotypes. The animals were obtained by controlled breeding under uniform environmental conditions. The mutant animals all had uniformly and significantly lower serum phosphate levels, shorter tail length and higher 24-hydroxylase activity relative to unaffected litter-mates. There was no evidence of a gene dose effect because values were not significantly different among the three mutant genotypes. We also studied the influence of gamete of origin on serum phosphate, tail length and renal mitochondrial 24-hydroxylase activity in the Hyp/+ offspring of affected males (Hyp/Y) or affected females (Hyp/+ or Hyp/Hyp). We found no effect on the distribution of trait values. We conclude that parental origin of mutant allele does not explain the absence of a gene dose effect in Hyp mice.
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Affiliation(s)
- Z Q Qiu
- Department of Biology, McGill University, Montreal, Quebec, Canada
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Qiu ZQ, Pearson J, Bader SD. Asymmetry of the spin reorientation transition in ultrathin Fe films and wedges grown on Ag(100). Phys Rev Lett 1993; 70:1006-1009. [PMID: 10054260 DOI: 10.1103/physrevlett.70.1006] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Qiu ZQ, Pearson J, Bader SD. Oscillatory interlayer magnetic coupling of wedged Co/Cu/Co sandwiches grown on Cu(100) by molecular beam epitaxy. Phys Rev B Condens Matter 1992; 46:8659-8662. [PMID: 10002647 DOI: 10.1103/physrevb.46.8659] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Qiu ZQ, Pearson J, Bader SD. Magneto-optic Kerr ellipticity of epitaxial Co/Cu overlayers and superlattices. Phys Rev B Condens Matter 1992; 46:8195-8200. [PMID: 10002577 DOI: 10.1103/physrevb.46.8195] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Qiu ZQ, Pearson J, Bader SD. Additivity of the magneto-optic Kerr signal in ultrathin Fe(110)/Ag(111) superlattices. Phys Rev B Condens Matter 1992; 45:7211-7216. [PMID: 10000492 DOI: 10.1103/physrevb.45.7211] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Qiu ZQ, Pearson J, Berger A, Bader SD. Short-period oscillations in the interlayer magnetic coupling of wedged Fe(100)/Mo(100)/Fe(100) grown on Mo(100) by molecular-beam epitaxy. Phys Rev Lett 1992; 68:1398-1401. [PMID: 10046156 DOI: 10.1103/physrevlett.68.1398] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Qiu ZQ, Mattson JE, Sowers CH, Welp U, Bader SD, Tang H, Walker JC. Temperature dependence of the magnetization of superlattices with variable interlayer magnetic couplings. Phys Rev B Condens Matter 1992; 45:2252-2257. [PMID: 10001744 DOI: 10.1103/physrevb.45.2252] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Gutierrez CJ, Qiu ZQ, Tang H, Wieczorek MD, Mayer SH, Walker JC. Indirect magnetic interaction through silver in epitaxial Fe(110)/Ag(111) multilayers. Phys Rev B Condens Matter 1991; 44:2190-2197. [PMID: 9999768 DOI: 10.1103/physrevb.44.2190] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Qiu ZQ, Mayer SH, Gutierrez CJ, Tang H, Walker JC. Thermal magnetic relaxation in quasi-two-dimensional Fe films. Phys Rev Lett 1989; 63:1649-1652. [PMID: 10040633 DOI: 10.1103/physrevlett.63.1649] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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