1
|
Feng J, Zhou X, Xu M, Shi J, Li Y. Layer Control of Magneto-Optical Effects and Their Quantization in Spin-Valley Splitting Antiferromagnets. NANO LETTERS 2024; 24:3898-3905. [PMID: 38525906 DOI: 10.1021/acs.nanolett.3c05052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/26/2024]
Abstract
Magneto-optical effects (MOE), interfacing the fundamental interplay between magnetism and light, have served as a powerful probe for magnetic order, band topology, and valley index. Here, based on multiferroic and topological bilayer antiferromagnets (AFMs), we propose a layer control of MOE (L-MOE), which is created and annihilated by layer-stacking or an electric field effect. The key character of L-MOE is the sign-reversible response controlled by ferroelectric polarization, the Néel vector, or the electric field direction. Moreover, the sign-reversible L-MOE can be quantized in topologically insulating AFMs. We reveal that the switchable L-MOE originates from the combined contributions of spin-conserving and spin-flip interband transitions in spin-valley splitting AFMs, a phenomenon not observed in conventional AFMs. Our findings bridge the ancient MOE to the emergent realms of layertronics, valleytronics, and multiferroics and may hold immense potential in these fields.
Collapse
Affiliation(s)
- Jiaqi Feng
- Laboratory of Quantum Functional Materials Design and Application, School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116, China
| | - Xiaodong Zhou
- Laboratory of Quantum Functional Materials Design and Application, School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116, China
| | - Meiling Xu
- Laboratory of Quantum Functional Materials Design and Application, School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116, China
| | - Jingming Shi
- Laboratory of Quantum Functional Materials Design and Application, School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116, China
| | - Yinwei Li
- Laboratory of Quantum Functional Materials Design and Application, School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116, China
| |
Collapse
|
2
|
Hubmann S, Budkin G, Urban M, Bel’kov V, Dmitriev A, Ziegler J, Kozlov D, Mikhailov N, Dvoretsky S, Kvon Z, Weiss D, Ganichev S. Impact Ionization Induced by Terahertz Radiation in HgTe Quantum Wells of Critical Thickness. JOURNAL OF INFRARED, MILLIMETER AND TERAHERTZ WAVES 2020; 41:1155-1169. [PMID: 34721704 PMCID: PMC8550783 DOI: 10.1007/s10762-020-00690-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 03/20/2020] [Indexed: 06/13/2023]
Abstract
We report on the observation of terahertz (THz) radiation induced band-to-band impact ionization in HgTe quantum well (QW) structures of critical thickness, which are characterized by a nearly linear energy dispersion. The THz electric field drives the carriers initializing electron-hole pair generation. The carrier multiplication is observed for photon energies less than the energy gap under the condition that the product of the radiation angular frequency ω and momentum relaxation time τ l larger than unity. In this case, the charge carriers acquire high energies solely because of collisions in the presence of a high-frequency electric field. The developed microscopic theory shows that the probability of the light-induced impact ionization is proportional to exp ( - E 0 2 / E 2 ) , with the radiation electric field amplitude E and the characteristic field parameter E 0. As observed in experiment, it exhibits a strong frequency dependence for ω τ ≫ 1 characterized by the characteristic field E 0 linearly increasing with the radiation frequency ω.
Collapse
Affiliation(s)
- S. Hubmann
- Terahertz Center, University of Regensburg, 93040 Regensburg, Germany
| | - G.V. Budkin
- Ioffe Institute, 194021 St. Petersburg, Russia
| | - M. Urban
- Terahertz Center, University of Regensburg, 93040 Regensburg, Germany
| | | | | | - J. Ziegler
- Terahertz Center, University of Regensburg, 93040 Regensburg, Germany
| | - D.A. Kozlov
- Rzhanov Institute of Semiconductor Physics, 630090 Novosibirsk, Russia
| | - N.N. Mikhailov
- Rzhanov Institute of Semiconductor Physics, 630090 Novosibirsk, Russia
| | - S.A. Dvoretsky
- Rzhanov Institute of Semiconductor Physics, 630090 Novosibirsk, Russia
| | - Z.D. Kvon
- Rzhanov Institute of Semiconductor Physics, 630090 Novosibirsk, Russia
| | - D. Weiss
- Terahertz Center, University of Regensburg, 93040 Regensburg, Germany
| | - S.D. Ganichev
- Terahertz Center, University of Regensburg, 93040 Regensburg, Germany
| |
Collapse
|
3
|
Feng W, Hanke JP, Zhou X, Guo GY, Blügel S, Mokrousov Y, Yao Y. Topological magneto-optical effects and their quantization in noncoplanar antiferromagnets. Nat Commun 2020; 11:118. [PMID: 31913308 PMCID: PMC6949225 DOI: 10.1038/s41467-019-13968-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 12/10/2019] [Indexed: 11/23/2022] Open
Abstract
Reflecting the fundamental interactions of polarized light with magnetic matter, magneto-optical effects are well known since more than a century. The emergence of these phenomena is commonly attributed to the interplay between exchange splitting and spin-orbit coupling in the electronic structure of magnets. Using theoretical arguments, we demonstrate that topological magneto-optical effects can arise in noncoplanar antiferromagnets due to the finite scalar spin chirality, without any reference to exchange splitting or spin-orbit coupling. We propose spectral integrals of certain magneto-optical quantities that uncover the unique topological nature of the discovered effect. We also find that the Kerr and Faraday rotation angles can be quantized in insulating topological antiferromagnets in the low-frequency limit, owing to nontrivial global properties that manifest in quantum topological magneto-optical effects. Although the predicted topological and quantum topological magneto-optical effects are fundamentally distinct from conventional light-matter interactions, they can be measured by readily available experimental techniques.
Collapse
Affiliation(s)
- Wanxiang Feng
- Key Lab of advanced optoelectronic quantum architecture and measurement (Ministry of Education), Beijing Key Lab of Nanophotonics & Ultrafine Optoelectronic Systems, and School of Physics, Beijing Institute of Technology, 100081, Beijing, China
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425, Jülich, Germany
| | - Jan-Philipp Hanke
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425, Jülich, Germany
- Institute of Physics, Johannes Gutenberg University Mainz, 55099, Mainz, Germany
| | - Xiaodong Zhou
- Key Lab of advanced optoelectronic quantum architecture and measurement (Ministry of Education), Beijing Key Lab of Nanophotonics & Ultrafine Optoelectronic Systems, and School of Physics, Beijing Institute of Technology, 100081, Beijing, China
| | - Guang-Yu Guo
- Department of Physics and Center for Theoretical Physics, National Taiwan University, Taipei, 10617, Taiwan
- Physics Division, National Center for Theoretical Sciences, Hsinchu, 30013, Taiwan
| | - Stefan Blügel
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425, Jülich, Germany
| | - Yuriy Mokrousov
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425, Jülich, Germany
- Institute of Physics, Johannes Gutenberg University Mainz, 55099, Mainz, Germany
| | - Yugui Yao
- Key Lab of advanced optoelectronic quantum architecture and measurement (Ministry of Education), Beijing Key Lab of Nanophotonics & Ultrafine Optoelectronic Systems, and School of Physics, Beijing Institute of Technology, 100081, Beijing, China.
| |
Collapse
|
4
|
Zhou X, Zhang RW, Zhang Z, Ma DS, Feng W, Mokrousov Y, Yao Y. Fully Spin-Polarized Nodal Loop Semimetals in Alkaline Metal Monochalcogenide Monolayers. J Phys Chem Lett 2019; 10:3101-3108. [PMID: 31117678 DOI: 10.1021/acs.jpclett.9b00906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Topological semimetals in ferromagnetic materials have attracted an enormous amount of attention due to potential applications in spintronics. Using first-principles density functional theory together with an effective lattice model, here we present a new family of topological semimetals with a fully spin-polarized nodal loop in alkaline metal monochalcogenide MX (M = Li, Na, K, Rb, or Cs; X = S, Se, or Te) monolayers. The half-metallic ferromagnetism can be established in MX monolayers, in which one nodal loop formed by two crossing bands with the same spin components is found at the Fermi energy. This nodal loop half-metal survives even when considering the spin-orbit coupling owing to the symmetry protection provided by the Mz mirror plane. The quantum anomalous Hall state and Weyl-like semimetal in this system can be also achieved by rotating the spin from the out-of-plane to the in-plane direction. The MX monolayers hosting rich topological phases thus offer an excellent platform for realizing advanced spintronic concepts.
Collapse
Affiliation(s)
- Xiaodong Zhou
- Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), Beijing Key Lab of Nanophotonics Ultrafine Optoelectronic Systems, and School of Physics , Beijing Institute of Technology , Beijing 100081 , China
| | - Run-Wu Zhang
- Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), Beijing Key Lab of Nanophotonics Ultrafine Optoelectronic Systems, and School of Physics , Beijing Institute of Technology , Beijing 100081 , China
| | - Zeying Zhang
- Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), Beijing Key Lab of Nanophotonics Ultrafine Optoelectronic Systems, and School of Physics , Beijing Institute of Technology , Beijing 100081 , China
| | - Da-Shuai Ma
- Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), Beijing Key Lab of Nanophotonics Ultrafine Optoelectronic Systems, and School of Physics , Beijing Institute of Technology , Beijing 100081 , China
| | - Wanxiang Feng
- Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), Beijing Key Lab of Nanophotonics Ultrafine Optoelectronic Systems, and School of Physics , Beijing Institute of Technology , Beijing 100081 , China
- Peter Grünberg Institut and Institute for Advanced Simulation , Forschungszentrum Jülich and JARA , D-52425 Jülich , Germany
| | - Yuriy Mokrousov
- Peter Grünberg Institut and Institute for Advanced Simulation , Forschungszentrum Jülich and JARA , D-52425 Jülich , Germany
- Institute of Physics , Johannes Gutenberg University Mainz , 55099 Mainz , Germany
| | - Yugui Yao
- Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), Beijing Key Lab of Nanophotonics Ultrafine Optoelectronic Systems, and School of Physics , Beijing Institute of Technology , Beijing 100081 , China
| |
Collapse
|
5
|
Bovkun LS, Ikonnikov AV, Aleshkin VY, Spirin KE, Gavrilenko VI, Mikhailov NN, Dvoretskii SA, Teppe F, Piot BA, Potemski M, Orlita M. Landau level spectroscopy of valence bands in HgTe quantum wells: effects of symmetry lowering. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:145501. [PMID: 30634183 DOI: 10.1088/1361-648x/aafdf0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The Landau level spectroscopy technique has been used to explore the electronic structure of the valence band in a series of p-type HgTe/HgCdTe quantum wells with both normal and inverted ordering of bands. We find that the standard axial-symmetric 4-band Kane model, which is nowadays widely applied in physics of HgTe-based topological materials, does not fully account for the complex magneto-optical response observed in our experiments-notably, for the unexpected avoided crossings of excitations and for the appearance of transitions that are electric-dipole forbidden within this model. Nevertheless, reasonable agreement with experiments is achieved when the standard model is expanded to include effects of bulk and interface inversion asymmetries. These remove the axial symmetry, and among other, profoundly modify the shape of valence bands.
Collapse
Affiliation(s)
- L S Bovkun
- Institute for Physics of Microstructures RAS, 603950 Nizhny Novgorod, Russia. Laboratoire National des Champs Magnétiques Intenses, LNCMI-CNRS-UGA-UPS-INSA-EMFL, 38042 Grenoble, France
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Shao Y, Post KW, Wu JS, Dai S, Frenzel AJ, Richardella AR, Lee JS, Samarth N, Fogler MM, Balatsky AV, Kharzeev DE, Basov DN. Faraday Rotation Due to Surface States in the Topological Insulator (Bi 1-xSb x) 2Te 3. NANO LETTERS 2017; 17:980-984. [PMID: 28030948 DOI: 10.1021/acs.nanolett.6b04313] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Using magneto-infrared spectroscopy, we have explored the charge dynamics of (Bi,Sb)2Te3 thin films on InP substrates. From the magneto-transmission data we extracted three distinct cyclotron resonance (CR) energies that are all apparent in the broad band Faraday rotation (FR) spectra. This comprehensive FR-CR data set has allowed us to isolate the response of the bulk states from the intrinsic surface states associated with both the top and bottom surfaces of the film. The FR data uncovered that electron- and hole-type Dirac Fermions reside on opposite surfaces of our films, which paves the way for observing many exotic quantum phenomena in topological insulators.
Collapse
Affiliation(s)
- Yinming Shao
- Department of Physics, Columbia University , New York, New York 10027, United States
| | - Kirk W Post
- Physics Department, University of California-San Diego , La Jolla, California 92093, United States
| | - Jhih-Sheng Wu
- Physics Department, University of California-San Diego , La Jolla, California 92093, United States
| | - Siyuan Dai
- Physics Department, University of California-San Diego , La Jolla, California 92093, United States
| | - Alex J Frenzel
- Physics Department, University of California-San Diego , La Jolla, California 92093, United States
| | - Anthony R Richardella
- Department of Physics, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Joon Sue Lee
- Department of Physics, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Nitin Samarth
- Department of Physics, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Michael M Fogler
- Physics Department, University of California-San Diego , La Jolla, California 92093, United States
| | - Alexander V Balatsky
- Nordita, KTH Royal Institute of Technology and Stockholm University , Roslagstullsbacken 23, SE-106 91 Stockholm, Sweden
- Institute for Materials Science, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Dmitri E Kharzeev
- Department of Physics and Astronomy, Stony Brook University , Stony Brook, New York 11794-3800, United States
- Department of Physics and RIKEN-BNL Research Center, Brookhaven National Laboratory , Upton, New York 11973, United States
| | - D N Basov
- Department of Physics, Columbia University , New York, New York 10027, United States
- Physics Department, University of California-San Diego , La Jolla, California 92093, United States
| |
Collapse
|