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Liang G, Zhai G, Ma J, Wang H, Zhao J, Wu X, Zhang X. Circular Photogalvanic Current in Ni-Doped Cd 3As 2 Films Epitaxied on GaAs(111)B Substrate. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:1979. [PMID: 37446495 DOI: 10.3390/nano13131979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 06/26/2023] [Accepted: 06/28/2023] [Indexed: 07/15/2023]
Abstract
Magnetic element doped Cd3As2 Dirac semimetal has attracted great attention for revealing the novel quantum phenomena and infrared opto-electronic applications. In this work, the circular photogalvanic effect (CPGE) was investigated at various temperatures for the Ni-doped Cd3As2 films which were grown on GaAs(111)B substrate by molecular beam epitaxy. The CPGE current generation was found to originate from the structural symmetry breaking induced by the lattice strain and magnetic doping in the Ni-doped Cd3As2 films, similar to that in the undoped ones. However, the CPGE current generated in the Ni-doped Cd3As2 films was approximately two orders of magnitude smaller than that in the undoped one under the same experimental conditions and exhibited a complex temperature variation. While the CPGE current in the undoped film showed a general increase with rising temperature. The greatly reduced CPGE current generation efficiency and its complex variation with temperature in the Ni-doped Cd3As2 films was discussed to result from the efficient capture of photo-generated carriers by the deep-level magnetic impurity bands and enhanced momentum relaxation caused by additional strong impurity scattering when magnetic dopants were introduced.
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Affiliation(s)
- Gaoming Liang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guihao Zhai
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jialin Ma
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hailong Wang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jianhua Zhao
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoguang Wu
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xinhui Zhang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
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Liang G, Zhai G, Ma J, Wang H, Zhao J, Wu X, Zhang X. Strain-induced circular photogalvanic current in Dirac semimetal Cd 3As 2 films epitaxied on a GaAs(111)B substrate. NANOSCALE 2022; 14:2383-2392. [PMID: 35088779 DOI: 10.1039/d1nr05812f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Dirac semimetal (DSM) Cd3As2 has drawn great attention for exploring the novel quantum phenomena and high-speed optoelectronic applications. The circular photogalvanic effect (CPGE) current, resulting from the optically-excited spin orientation transport, was theoretically predicted to vanish in an ideal Dirac system due to the symmetric photoexcitation about the Dirac point. Here, we reported the observation of the CPGE photocurrent in epitaxial Cd3As2 thin films grown on a GaAs(111)B substrate. The signature of the CPGE is confirmed by its sign reversal upon switching the helicity of optical radiation, as well as its dependence on the excitation incident angle and power. By comparison of the CPGE response between the films with different thicknesses, it is suggested that the observed CPGE results from the reduced structure symmetry and substantially modified electronic band structure of the Cd3As2 thin film that undergoes large epitaxial strain. Our experimental findings provide a valuable reference for the band engineering and exotic helicity-dependent photocurrent phenomena in DSMs towards their potential opto-spintronic device applications.
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Affiliation(s)
- Gaoming Liang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, P. R. China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Guihao Zhai
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, P. R. China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jialin Ma
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, P. R. China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Hailong Wang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, P. R. China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jianhua Zhao
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, P. R. China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Xiaoguang Wu
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, P. R. China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Xinhui Zhang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, P. R. China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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Yan Q, Li Z, Zhou P, Sun L. Nontrivial topological states in new two-dimensional CdAs. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:365701. [PMID: 34144543 DOI: 10.1088/1361-648x/ac0cb5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 06/18/2021] [Indexed: 06/12/2023]
Abstract
By using first-principles calculations and symmetry analysis, we propose two topological nontrivial two-dimensional (2D) materials: CdAs-164 and CdAs-187. The results of binding energies, phonon dispersions, mechanical constants and thermodynamic stability demonstrate that the two materials are stable and may be synthesized in future experiments. When spin-orbit coupling (SOC) is not considered, the former is a typical Dirac semimetal with six equivalent Dirac points on the paths of Γ-M. These Dirac points are protected by vertical mirror symmetry. The latter is a nodal ring semimetal with the coexistence of two type-I nodal rings and one type-II nodal ring, and these nodal rings are protected by the horizontal mirror operationσh. After SOC is considered, both of the two materials turn into topological insulators withZ2= 1. Our findings indicate that CdAs-164 and CdAs-187 are excellent candidates to explore the nontrivial topological states of 2D materials.
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Affiliation(s)
- Quihui Yan
- Hunan Provincial Key laboratory of Thin Film Materials and Devices, School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Zehou Li
- Hunan Provincial Key laboratory of Thin Film Materials and Devices, School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Pan Zhou
- Hunan Provincial Key laboratory of Thin Film Materials and Devices, School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Lizhong Sun
- Hunan Provincial Key laboratory of Thin Film Materials and Devices, School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, People's Republic of China
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4
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Xu H. Realization of Opened and Closed Nodal Lines and Four- and Three-fold Degenerate Nodal Points in XPt (X = Sc, Y, La) Intermetallic Compound: A Computational Modeling Study. Front Chem 2020; 8:609118. [PMID: 33251188 PMCID: PMC7674926 DOI: 10.3389/fchem.2020.609118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 10/12/2020] [Indexed: 11/13/2022] Open
Abstract
Realizing rich topological elements in topological materials has attracted increasing attention in the fields of chemistry, physics, and materials science. Topological semimetals/metals are classified into three main types: nodal-point, nodal-line, and nodal-surface types with zero-, one-, and two-dimensional topological elements, respectively. This study reports that XPt (X = Sc, Y, La) intermetallic compounds are topological metals with opened and closed nodal lines, and triply degenerate nodal points (TNPs) when the spin-orbit coupling (SOC) is ignored. Based on the calculated phonon dispersions, one can find that ScPt and YPt are dynamically stable whereas LaPt is not. When SOC is added, the one-dimensional nodal line and zero-dimensional TNPs disappear. Interestingly, a new zero-dimensional topological element, that is, Dirac points with 4-fold degenerate isolated band crossings with linear band dispersion appear. The proposed materials can be considered a good platform to realize zero- and one-dimensional topological elements in a single compound and to study the relationship between zero- and one-dimensional topological elements.
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Affiliation(s)
- Heju Xu
- College of Science, North China University of Science and Technology, Tangshan, China
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5
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Li Y, Xia J. Cubic Hafnium Nitride: A Novel Topological Semimetal Hosting a 0-Dimensional (0-D) Nodal Point and a 1-D Topological Nodal Ring. Front Chem 2020; 8:727. [PMID: 33005603 PMCID: PMC7479206 DOI: 10.3389/fchem.2020.00727] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 07/14/2020] [Indexed: 11/13/2022] Open
Abstract
Very recently, topological semimetals with nontrivial band crossing and associated topological surface states have received widespread attention. Various types of topological semimetals, including nodal point semimetals, nodal line semimetals, and nodal surface semimetals, have been predicted from first principles. In absence of spin-orbit coupling (SOC) effect, we propose that cubic-type hafnium nitride (HfN) with a P m 3 ¯ m space group is a novel topological semimetal hosting a rare 0-D triple nodal point and a 1-D topological nodal ring. More importantly, the interesting 0-D and 1-D topological states all occur near the Fermi level, and these topological states are not disturbed by other extraneous bands. When the SOC effect is taken into consideration, 0-D triple nodal point was gapped and a new 0-D topological element, namely, Dirac point appears along Γ-R path. Finally, the dynamical and mechanical stabilities of this semimetal and its associated mechanical properties are discussed in order to provide a reference for future investigations. Our work promises that HfN can serve as a superior topological semimetal with high stability, excellent mechanical properties, and rich topological states.
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Affiliation(s)
- Yang Li
- Department of Physics, Chongqing University of Arts and Sciences, Chongqing, China.,Faculty of Mechanical and Electrical Engineering, Kunming University of Science and Technology, Kunming, China
| | - Jihong Xia
- Department of Physics, Chongqing University of Arts and Sciences, Chongqing, China
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6
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Sun Y, Meng Y, Dai R, Yang Y, Xu Y, Zhu S, Shi Y, Xiu F, Wang F. Slowing down photocarrier relaxation in Dirac semimetal Cd 3As 2 via Mn doping. OPTICS LETTERS 2019; 44:4103-4106. [PMID: 31465339 DOI: 10.1364/ol.44.004103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 07/20/2019] [Indexed: 06/10/2023]
Abstract
In this Letter, we successfully introduce a long-lived non-radiative photocarrier decay component in a Dirac semimetal Cd3As2 thin film via Mn doping. The long-lived decay component is found to vary between 200 ps and 2.8 ns with different Mn concentrations and probing wavelengths. Most remarkably, the elongated transients persist over the important mid-infrared wavelengths (observed up to 4 μm). Saturable absorption measurement reveals stronger modulation effects for long-width pulses (∼80 ps) from the Mn-doped samples. Our results provide new insights into the effect of transition-metal doping on the ultrafast optical properties of Dirac semimetal Cd3As2 and establish Cd3As2 as a highly amendable material for mid-infrared photonic applications.
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7
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Yang M, Wang J, Yang Y, Zhang Q, Ji C, Wu G, Su Y, Gou J, Wu Z, Yuan K, Xiu F, Jiang Y. Ultraviolet to Long-Wave Infrared Photodetectors Based on a Three-Dimensional Dirac Semimetal/Organic Thin Film Heterojunction. J Phys Chem Lett 2019; 10:3914-3921. [PMID: 31248258 DOI: 10.1021/acs.jpclett.9b01619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In this work, high-performance ultraviolet to long-wave infrared (UV-LIR) devices based on an N-type three-dimensional (3D) Dirac semimetal Cd3As2 and P-type organic (small molecules and polymers) heterojunction are prepared. Primarily, the photodetector shows a broadband photoresponse from 365 to 10600 nm. The optimized device responsivity is 729 mA/W, along with a fast response time of 282 μs and a high on-off ratio of 6268, which are 2 orders of magnitude higher than those previously reported for a 3D Dirac semimetal-based device. In the LIR region (10600 nm), the responsivity and on-off ratio can reach 81.3 mA/W and 100, respectively. In addition, the time-resolved femtosecond pump detection technology is used to reveal the relaxation time of Cd3As2/organic thin films (4.30 ps), indicating that Cd3As2/organic thin films have great potential for the manufacture of fast IR devices. These results demonstrate that the 3D Dirac semimetal/organic thin film heterojunction photodetectors will be a feasible solution for high-speed and broadband photodetectors in large-array imaging.
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Affiliation(s)
- Ming Yang
- School of Optoelectronic Science and Engineering , University of Electronic Science and Technology of China , Chengdu 610054 , P. R. China
| | - Jun Wang
- School of Optoelectronic Science and Engineering , University of Electronic Science and Technology of China , Chengdu 610054 , P. R. China
- State Key Laboratory of Electronic Thin Films and Integrated Devices , University of Electronic Science and Technology of China , Chengdu 610054 , P. R. China
| | - Yunkun Yang
- State Key Laboratory of Surface Physics and Department of Physics , Fudan University , Shanghai 200433 , P. R. China
| | - Qi Zhang
- State Key Laboratory of Molecular Reaction Dynamics , Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023 , P. R. China
| | - Chunhui Ji
- School of Optoelectronic Science and Engineering , University of Electronic Science and Technology of China , Chengdu 610054 , P. R. China
| | - Guorong Wu
- State Key Laboratory of Molecular Reaction Dynamics , Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023 , P. R. China
| | - Yuanjie Su
- School of Optoelectronic Science and Engineering , University of Electronic Science and Technology of China , Chengdu 610054 , P. R. China
| | - Jun Gou
- School of Optoelectronic Science and Engineering , University of Electronic Science and Technology of China , Chengdu 610054 , P. R. China
| | - Zhiming Wu
- School of Optoelectronic Science and Engineering , University of Electronic Science and Technology of China , Chengdu 610054 , P. R. China
- State Key Laboratory of Electronic Thin Films and Integrated Devices , University of Electronic Science and Technology of China , Chengdu 610054 , P. R. China
| | - Kaijun Yuan
- State Key Laboratory of Molecular Reaction Dynamics , Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023 , P. R. China
| | - Faxian Xiu
- State Key Laboratory of Surface Physics and Department of Physics , Fudan University , Shanghai 200433 , P. R. China
- Collaborative Innovation Center of Advanced Microstructures , Nanjing 210093 , China
| | - Yadong Jiang
- School of Optoelectronic Science and Engineering , University of Electronic Science and Technology of China , Chengdu 610054 , P. R. China
- State Key Laboratory of Electronic Thin Films and Integrated Devices , University of Electronic Science and Technology of China , Chengdu 610054 , P. R. China
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8
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Yuan X, Yan Z, Song C, Zhang M, Li Z, Zhang C, Liu Y, Wang W, Zhao M, Lin Z, Xie T, Ludwig J, Jiang Y, Zhang X, Shang C, Ye Z, Wang J, Chen F, Xia Z, Smirnov D, Chen X, Wang Z, Yan H, Xiu F. Chiral Landau levels in Weyl semimetal NbAs with multiple topological carriers. Nat Commun 2018; 9:1854. [PMID: 29748535 PMCID: PMC5945645 DOI: 10.1038/s41467-018-04080-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 04/04/2018] [Indexed: 11/09/2022] Open
Abstract
Recently, Weyl semimetals have been experimentally discovered in both inversion-symmetry-breaking and time-reversal-symmetry-breaking crystals. The non-trivial topology in Weyl semimetals can manifest itself with exotic phenomena, which have been extensively investigated by photoemission and transport measurements. Despite the numerous experimental efforts on Fermi arcs and chiral anomaly, the existence of unconventional zeroth Landau levels, as a unique hallmark of Weyl fermions, which is highly related to chiral anomaly, remains elusive owing to the stringent experimental requirements. Here, we report the magneto-optical study of Landau quantization in Weyl semimetal NbAs. High magnetic fields drive the system toward the quantum limit, which leads to the observation of zeroth chiral Landau levels in two inequivalent Weyl nodes. As compared to other Landau levels, the zeroth chiral Landau level exhibits a distinct linear dispersion in magnetic field direction and allows the optical transitions without the limitation of zero z momentum or [Formula: see text] magnetic field evolution. The magnetic field dependence of the zeroth Landau levels further verifies the predicted particle-hole asymmetry of the Weyl cones. Meanwhile, the optical transitions from the normal Landau levels exhibit the coexistence of multiple carriers including an unexpected massive Dirac fermion, pointing to a more complex topological nature in inversion-symmetry-breaking Weyl semimetals. Our results provide insights into the Landau quantization of Weyl fermions and demonstrate an effective tool for studying complex topological systems.
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Affiliation(s)
- Xiang Yuan
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China.,Collaborative Innovation Center of Advanced Microstructures, Fudan University, 200433, Shanghai, China
| | - Zhongbo Yan
- Institute for Advanced Study, Tsinghua University, 100084, Beijing, China
| | - Chaoyu Song
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China.,Collaborative Innovation Center of Advanced Microstructures, Fudan University, 200433, Shanghai, China
| | - Mengyao Zhang
- International Center for Quantum Materials, School of Physics, Peking University, 100871, Beijing, China.,Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
| | - Zhilin Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China.,Collaborative Innovation Center of Quantum Matter, 100871, Beijing, China
| | - Cheng Zhang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China.,Collaborative Innovation Center of Advanced Microstructures, Fudan University, 200433, Shanghai, China
| | - Yanwen Liu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China.,Collaborative Innovation Center of Advanced Microstructures, Fudan University, 200433, Shanghai, China
| | - Weiyi Wang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China.,Collaborative Innovation Center of Advanced Microstructures, Fudan University, 200433, Shanghai, China
| | - Minhao Zhao
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China.,Collaborative Innovation Center of Advanced Microstructures, Fudan University, 200433, Shanghai, China
| | - Zehao Lin
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China.,Collaborative Innovation Center of Advanced Microstructures, Fudan University, 200433, Shanghai, China
| | - Tian Xie
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China.,Collaborative Innovation Center of Advanced Microstructures, Fudan University, 200433, Shanghai, China
| | - Jonathan Ludwig
- National High Magnetic Field Laboratory, Tallahassee, Florida, 32310, USA
| | - Yuxuan Jiang
- National High Magnetic Field Laboratory, Tallahassee, Florida, 32310, USA
| | - Xiaoxing Zhang
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, 430074, Wuhan, China
| | - Cui Shang
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, 430074, Wuhan, China
| | - Zefang Ye
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China.,Collaborative Innovation Center of Advanced Microstructures, Fudan University, 200433, Shanghai, China
| | - Jiaxiang Wang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China.,Collaborative Innovation Center of Advanced Microstructures, Fudan University, 200433, Shanghai, China
| | - Feng Chen
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China.,Collaborative Innovation Center of Advanced Microstructures, Fudan University, 200433, Shanghai, China
| | - Zhengcai Xia
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, 430074, Wuhan, China
| | - Dmitry Smirnov
- National High Magnetic Field Laboratory, Tallahassee, Florida, 32310, USA
| | - Xiaolong Chen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China.,Collaborative Innovation Center of Quantum Matter, 100871, Beijing, China
| | - Zhong Wang
- Institute for Advanced Study, Tsinghua University, 100084, Beijing, China.,Collaborative Innovation Center of Quantum Matter, 100871, Beijing, China
| | - Hugen Yan
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China. .,Collaborative Innovation Center of Advanced Microstructures, Fudan University, 200433, Shanghai, China.
| | - Faxian Xiu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China. .,Collaborative Innovation Center of Advanced Microstructures, Fudan University, 200433, Shanghai, China. .,Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, 200433, Shanghai, China.
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9
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A robust and tuneable mid-infrared optical switch enabled by bulk Dirac fermions. Nat Commun 2017; 8:14111. [PMID: 28106037 PMCID: PMC5263875 DOI: 10.1038/ncomms14111] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 11/29/2016] [Indexed: 12/24/2022] Open
Abstract
Pulsed lasers operating in the mid-infrared (3-20 μm) are important for a wide range of applications in sensing, spectroscopy, imaging and communications. Despite recent advances with mid-infrared gain platforms, the lack of a capable pulse generation mechanism remains a significant technological challenge. Here we show that bulk Dirac fermions in molecular beam epitaxy grown crystalline Cd3As2, a three-dimensional topological Dirac semimetal, constitutes an exceptional ultrafast optical switching mechanism for the mid-infrared. Significantly, we show robust and effective tuning of the scattering channels of Dirac fermions via an element doping approach, where photocarrier relaxation times are found flexibly controlled over an order of magnitude (from 8 ps to 800 fs at 4.5 μm). Our findings reveal the strong impact of Cr doping on ultrafast optical properties in Cd3As2 and open up the long sought parameter space crucial for the development of compact and high-performance mid-infrared ultrafast sources.
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