1
|
Hiraishi M, Okabe H, Koda A, Kadono R, Muroi T, Hirai D, Hiroi Z. Nonmagnetic Ground State in RuO_{2} Revealed by Muon Spin Rotation. Phys Rev Lett 2024; 132:166702. [PMID: 38701457 DOI: 10.1103/physrevlett.132.166702] [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] [Received: 09/13/2023] [Revised: 03/07/2024] [Accepted: 03/14/2024] [Indexed: 05/05/2024]
Abstract
The magnetic ground state of single crystalline RuO_{2} was investigated by the muon spin rotation and relaxation (μSR) experiment. The spin precession signal due to the spontaneous internal magnetic field B_{loc}, which is expected in the magnetically ordered phase, was not observed in the temperature range 5-400 K. Muon sites were evaluated by first-principles calculations using dilute hydrogen simulating muon as pseudohydrogen, and B_{loc} was simulated for the antiferromagnetic structures with a Ru magnetic moment |m_{Ru}|≈0.05μ_{B} suggested from diffraction experiments. As a result, the possibility was ruled out that muons are localized at sites where B_{loc} accidentally cancels. Conversely, assuming that the slow relaxation observed in μSR spectra was part of the precession signal, the upper limit for the magnitude of |m_{Ru}| was estimated to be 4.8(2)×10^{-4}μ_{B}, which is significantly less than 0.05μ_{B}. These results indicate that the antiferromagnetic order, as reported, is unlikely to exist in the bulk crystal.
Collapse
Affiliation(s)
- M Hiraishi
- Graduate School of Science and Engineering, Ibaraki University, Mito, Ibaraki 310-8512, Japan
- Muon Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - H Okabe
- Muon Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- Institute for Materials Research, Tohoku University (IMR), Aoba-ku, Sendai 980-8577, Japan
| | - A Koda
- Muon Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
- Graduate University for Advanced Studies, SOKENDAI
| | - R Kadono
- Muon Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
| | - T Muroi
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - D Hirai
- Department of Applied Physics, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan
| | - Z Hiroi
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| |
Collapse
|
2
|
Zvyagin SA, Ponomaryov AN, Wosnitza J, Hirai D, Hiroi Z, Gen M, Kohama Y, Matsuo A, Matsuda YH, Kindo K. Dimensional reduction and incommensurate dynamic correlations in the [Formula: see text] triangular-lattice antiferromagnet Ca 3ReO 5Cl 2. Nat Commun 2022; 13:6310. [PMID: 36274086 PMCID: PMC9588769 DOI: 10.1038/s41467-022-33992-5] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 10/07/2022] [Indexed: 12/03/2022] Open
Abstract
The observation of spinon excitations in the [Formula: see text] triangular antiferromagnet Ca3ReO5Cl2 reveals a quasi-one-dimensional (1D) nature of magnetic correlations, in spite of the nominally 2D magnetic structure. This phenomenon is known as frustration-induced dimensional reduction. Here, we present high-field electron spin resonance spectroscopy and magnetization studies of Ca3ReO5Cl2, allowing us not only to refine spin-Hamiltonian parameters, but also to investigate peculiarities of its low-energy spin dynamics. We argue that the presence of the uniform Dzyaloshinskii-Moriya interaction (DMI) shifts the spinon continuum in momentum space and, as a result, opens a zero-field gap at the Γ point. We observed this gap directly. The shift is found to be consistent with the structural modulation in the ordered state, suggesting this material as a perfect model triangular-lattice system, where a pure DMI-spiral ground state can be realized.
Collapse
Affiliation(s)
- S. A. Zvyagin
- Dresden High Magnetic Field Laboratory (HLD-EMFL) and Würzburg-Dresden Cluster of Excellence ct.qmat, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - A. N. Ponomaryov
- Dresden High Magnetic Field Laboratory (HLD-EMFL) and Würzburg-Dresden Cluster of Excellence ct.qmat, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
- Present Address: Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - J. Wosnitza
- Dresden High Magnetic Field Laboratory (HLD-EMFL) and Würzburg-Dresden Cluster of Excellence ct.qmat, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
- Institut für Festkörper- und Materialphysik, TU Dresden, 01062 Dresden, Germany
| | - D. Hirai
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 Japan
| | - Z. Hiroi
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 Japan
| | - M. Gen
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 Japan
| | - Y. Kohama
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 Japan
| | - A. Matsuo
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 Japan
| | - Y. H. Matsuda
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 Japan
| | - K. Kindo
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 Japan
| |
Collapse
|
3
|
Miyamoto D, Hirai D, Fung CCA, Inutsuka A, Odagawa M, Suzuki T, Boehringer R, Adaikkan C, Matsubara C, Matsuki N, Fukai T, McHugh TJ, Yamanaka A, Murayama M. Top-down cortical input during NREM sleep consolidates perceptual memory. Science 2016; 352:1315-8. [DOI: 10.1126/science.aaf0902] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Accepted: 05/12/2016] [Indexed: 12/30/2022]
|
4
|
Fujiyama S, Ohsumi H, Ohashi K, Hirai D, Kim BJ, Arima T, Takata M, Takagi H. Spin and orbital contributions to magnetically ordered moments in 5d layered perovskite Sr2IrO4. Phys Rev Lett 2014; 112:016405. [PMID: 24483915 DOI: 10.1103/physrevlett.112.016405] [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: 08/07/2013] [Indexed: 06/03/2023]
Abstract
The ratio of orbital (L) and spin (S) contributions to the magnetically ordered moments of a 5d transition metal oxide, Sr2IrO4 was evaluated by nonresonant magnetic x-ray diffraction. We applied an improved experimental setting that minimized the experimental error, in which we varied only the linear polarization of incident x ray at a fixed scattering angle. Strong polarization dependence of the intensity of magnetic diffraction was observed, from which we conclude that the ordered moments contain substantial contribution from the orbital degree of freedom with the ratio of <L>/<S>∼5.0, evidencing the pronounced effect of spin-orbit coupling. The obtained ratio is close to, but slightly larger than the expected value for the ideal J(eff) = 1/2 moment of a spin-orbital Mott insulator, |<J(1/2)|L(z)|J(1/2)>|/|<J(1/2)|S(z)|J(1/2)>| = 4, which cannot be accounted for by the redistribution of orbital components within the t(2g) bands associated with the elongation of the IrO6 octahedra.
Collapse
Affiliation(s)
- S Fujiyama
- RIKEN, Magnetic Materials Laboratory, Wako 351-0198, Japan
| | - H Ohsumi
- RIKEN, SPring-8 Center, Sayo, Hyogo 679-5148, Japan
| | - K Ohashi
- Department of Advanced Materials Science, University of Tokyo, Kashiwa 277-8561, Japan
| | - D Hirai
- Department of Physics, University of Tokyo, Tokyo 113-0033, Japan
| | - B J Kim
- Department of Advanced Materials Science, University of Tokyo, Kashiwa 277-8561, Japan
| | - T Arima
- RIKEN, SPring-8 Center, Sayo, Hyogo 679-5148, Japan and Department of Advanced Materials Science, University of Tokyo, Kashiwa 277-8561, Japan
| | - M Takata
- RIKEN, SPring-8 Center, Sayo, Hyogo 679-5148, Japan
| | - H Takagi
- RIKEN, Magnetic Materials Laboratory, Wako 351-0198, Japan and Department of Physics, University of Tokyo, Tokyo 113-0033, Japan
| |
Collapse
|
5
|
Takayama T, Kuwano K, Hirai D, Katsura Y, Yamamoto A, Takagi H. Strong coupling superconductivity at 8.4 K in an antiperovskite phosphide SrPt3P. Phys Rev Lett 2012; 108:237001. [PMID: 23003981 DOI: 10.1103/physrevlett.108.237001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 03/23/2012] [Indexed: 06/01/2023]
Abstract
We report the discovery of a family of ternary platinum phosphides APt3P (A = Ca, Sr, and La), which crystallize in an antiperovskite-based structure closely related to that of the heavy fermion superconductor CePt3Si. All three phosphides showed superconductivity at low temperatures and the highest critical temperature T(c) = 8.4 K was observed for SrPt3P. The analysis of specific heat C(T) for SrPt3P shows clear evidence for very strong coupling s-wave superconductivity with a large ratio between superconducting gap Δ0 and T(c), 2Δ0/k(B)T(c) ∼ 5, and the presence of low-energy phonons. The presence of multiple Fermi surface pockets was inferred from the nonlinear magnetic field dependence of Hall resistivity, which we argue might play a role in realizing the strong coupling of charge carriers with the low-lying phonons.
Collapse
Affiliation(s)
- T Takayama
- Department of Advanced Materials, University of Tokyo, and JST-TRIP, Kashiwa, Chiba 275-8651, Japan
| | | | | | | | | | | |
Collapse
|
6
|
Bremholm M, Yim CK, Hirai D, Climent-Pascual E, Xu Q, Zandbergen HW, Ali MN, Cava RJ. Destabilization of the 6H-SrIrO3 polymorph through partial substitution of zinc and lithium. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm32558f] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
7
|
Hirai D. Gelled droplet vitrification improves recovery of cryopreserved potato germplasm. Cryo Letters 2011; 32:287-296. [PMID: 22020408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The droplet vitrification method was improved for maneuverability by embedding shoot tips in gelled droplets before osmoprotection. This newly modified cryopreserving method -gelled droplet vitrification - was compared with other PVS2-based cryopreservation methods using potato shoot tips. Survival rates of each cryogenic procedure held at 25 degree C were about 40 percent by cryotube-vitrification procedures (vitrification and encapsulation vitrification methods) and about 70 percent by PVS2-droplet procedures (droplet vitrification and gelled droplet vitrification methods). Much higher cooling rates of PVS2-droplet procedures than cryotube- vitrification procedures increased their survival rates. The gelled droplet vitrification method was applied to shoot tips of 26 potato cultivars and six wild potatoes. After a little modifications of the conditions for preculture, osmoprotection and dehydration, all cultivars and wild potatoes produced high enough survival rates to be of value to genebanks and all surviving shoot tips developed normal shoots within 3 weeks.
Collapse
Affiliation(s)
- D Hirai
- Central Agricultural Experiment Station, Hokkaido Research Organization, Hokkaido, Japan.
| |
Collapse
|
8
|
Hirai D, Roseguini B, Diefenthaeler F, Carpes F, Vaz M, Ferlin E, Ribeiro J, Nakamura F. Effects of Altering Pedal Frequency on the Slow Component of PulmonaryV˙O2Kinetics and EMG Activity. Int J Sports Med 2010; 31:529-36. [DOI: 10.1055/s-0030-1251989] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
9
|
Hirai D, Sakai A. Simplified cryopreservation of sweet potato [ Ipomoea batatas (L.) Lam.] by optimizing conditions for osmoprotection. Plant Cell Rep 2003; 21:961-966. [PMID: 12835905 DOI: 10.1007/s00299-003-0618-5] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2002] [Revised: 02/12/2003] [Accepted: 02/20/2003] [Indexed: 05/24/2023]
Abstract
Shoot tips of sweet potato were successfully cryopreserved using an encapsulation vitrification method. Encapsulated shoot tips were pre-incubated in liquid Murashige-Skoog medium containing 30 g/l sucrose for 24 h, then precultured in sucrose-enriched medium (0.3 M sucrose) for 16 h. Shoot tips were osmoprotected with a mixture of 2 M glycerol and 1.6 M sucrose for 3 h before being dehydrated with a highly concentrated vitrification solution (PVS2) for 1 h at 25 degrees C. The encapsulated and dehydrated shoot tips were transferred to a 2 ml cryotube, suspended in 0.5 ml PVS2, and plunged directly into liquid nitrogen. Rapidly warmed shoot tips developed normal shoots and roots in 21 days without any morphological abnormalities after plating on a recovery medium. High levels (average of about 80%) of shoot formation were obtained for three cultivars of sweet potato. This encapsulation vitrification method appears promising for cryopreservation of sweet potato germplasm.
Collapse
Affiliation(s)
- D Hirai
- Hokkaido Central Agricultural Experiment Station, 069-1353 Naganuma, Hokkaido, Japan.
| | | |
Collapse
|
10
|
Sakai A, Matsumoto T, Hirai D, Niino T. Newly developed encapsulation-dehydration protocol for plantcryopreservation. Cryo Letters 2000; 21:53-62. [PMID: 12148065] [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: 02/26/2023]
Abstract
A simplified and efficient encapsulation-dehydration protocol, which is a compromise between vitrification and encapsulation-dehydration, was presented for plant cryopreservation. In this protocol, during the encapsulation process, the apices precultured with 0.3 M sucrose for 16 h were simultaneously osmoprotected with a mixture of 02 M glycerol plus 0.4 M sucrose for 1 h. These encapsulated apices were directly dehydrated with dry silica gel prior to a plunge into LN without the pretreatment of 0.8M sucrose for 16 h. This protocol produced much higher rates of recovery growth in the three plant species tested (wasabi, chrysanthemum, and mint) than those cryopreserved by the conventional encapsulation-dehydration. This protocol also considerably reduced the time needed for the cryogenic procedure. Thus, this new protocol appears promising for cryopreservation of shoot apices and other explants.
Collapse
Affiliation(s)
- A Sakai
- Hokkaido University, Asabucho 1-5-23, Kitaku, Sapporo, 001-0045 Japan
| | | | | | | |
Collapse
|
11
|
Hirai D, Sakai A. Cryopreservation of in vitro-grown axillary shoot-tip meristems of mint (Mentha spicata L.) by encapsulation vitrification. Plant Cell Rep 1999; 19:150-155. [PMID: 30754740 DOI: 10.1007/s002990050725] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Alginate-coated meristems from in vitro-grown axillary buds of mint (Mentha spicata L.) were successfully cryopreserved by vitrification. Excised meristems from nodal segments cold hardened at 4 °C for 3 weeks were encapsulated and osmoprotected by a mixture of 2 M glycerol plus 0.4 M sucrose. These meristems were dehydrated with a highly concentrated vitrification solution (PVS2 solution) for 3 h at 0 °C prior to a plunge into liquid nitrogen. Successfully encapsulated vitrified meristems developed shoots within a week after plating without intermediary callus formation. The average rate of shoot formation amounted to nearly 90%. This procedure was successfully applied to other Mentha species. It was also confirmed that encapsulated vitrified meristems produced a much higher rate of shoot formation than the encapsulated dried meristems. Thus, this revised encapsulation vitrification method appears promising for the cryopreservation of mint and other germplasm.
Collapse
Affiliation(s)
- D Hirai
- Hokkaido Prefectural Plant Genetic Resources Center, 363-2, Minami-takinokawa, Takikawa, 073-0013 Japan e-mail: Fax: +81(0) 125-24-3877, , , , , , JP
| | - A Sakai
- Asabucho 1-5-23, Kitaku, Sapporo 001-0045, Japan, , , , , , JP
| |
Collapse
|
12
|
Filipi CJ, Gaston-Johansson F, McBride PJ, Murayama K, Gerhardt J, Cornet DA, Lund RJ, Hirai D, Graham R, Patil K, Fitzgibbons R, Gaines RD. An assessment of pain and return to normal activity. Laparoscopic herniorrhaphy vs open tension-free Lichtenstein repair. Surg Endosc 1996; 10:983-6. [PMID: 8864090 DOI: 10.1007/s004649900219] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND Laparoscopic herniorrhaphy is controversial and deserves critical evaluation. METHODS In a randomized prospective study transabdominal preperitoneal laparoscopic herniorrhaphy (n = 24) was compared in patients to the tension-free Lichtenstein repair (n = 29) utilizing validated and reliable pain and activity assessment tools. The Sickness Impact Profile (SIP) was used to compare preoperative normal activity to postoperative activity. A Pain-O-Meter (visual analogue scale plus affective and sensory pain descriptors) assessed intensity of pain. The total pain assessment score and SIP were compared across time (postoperative day 1-42). Analgesic medication was used as a covariate. RESULTS The total pain score was less for laparoscopic herniorrhaphy but this did not reach statistical significance. Similarly, the SIP showed modest improvement for laparoscopic herniorrhaphy. No differences between groups were noted for morphine equivalents of administered analgesics or length of hospitalization. CONCLUSION Further investigation of laparoscopic herniorrhaphy is warranted.
Collapse
Affiliation(s)
- C J Filipi
- Creighton University School of Medicine, Department of Surgery, 601 N. 30th St., Omaha, NE 68131, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Hirai D. Gentamycin reduces bacteremia and mortality rates associated with the treatment of experimental peritonitis. J Am Coll Surg 1996; 182:282. [PMID: 8603256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
|
14
|
Hirai D. Reassessment of intraoperative decisions. Ann Surg 1981; 193:118-9. [PMID: 7458442 PMCID: PMC1345014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
|
15
|
Hirai D. Nasal Staphylococcus aureus and postoperative infection. Am Surg 1980; 46:310-2. [PMID: 7386998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Over a one-year period 19.5 per cent of 237 patients carried Staphylococcus aureus in their nares preoperatively. This rate was not influenced by the length of hospital stay. The patient nasal carrier state had no correlation with the incidence of postoperative infection. There was no outbreak of S. aureus infection during this period. It is well known that a long preoperative stay greatly increases the risk of infectious complications. This increase in infectious complications was not linked to nasal S. aureus colonization in this study. S. aureus was responsible for 19 per cent of postoperative infections in a 12-month period. S. aureus still occupies a significant place in nosocomial infection rates.
Collapse
|