1
|
Kong C, Song L, Zhao X, Wang H, Zhao J, Yuan G, Zhang X. Enhancing Magnetic Damping under GaAs Band-Edge Photoexcitation in a Co 2FeAl/ n-GaAs Heterojunction. ACS APPLIED MATERIALS & INTERFACES 2024; 16:17041-17050. [PMID: 38517684 DOI: 10.1021/acsami.4c01858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/24/2024]
Abstract
The ultrafast manipulation of spin in ferromagnet-semiconductor (FM/SC) heterojunctions is a key issue for advancing spintronics, where magnetic damping and interfacial spin transport often define device efficiency. Leveraging selective optical excitation in semiconductors offers a unique approach to spin manipulation in FM/SC heterojunctions. Herein, we investigated the magnetic dynamics of a Co2FeAl/n-GaAs heterojunction using the time-resolved magneto-optical Kerr technique and observed the considerably enhanced magnetic damping of Co2FeAl when GaAs is photoexcited near its band edge. This enhancement is attributed to an enhanced spin-pumping effect facilitated by spin-dependent carrier tunneling and capture within the Co2FeAl layer. Moreover, circularly polarized light excites spin-polarized band-edge photocarriers, further impacting the magnetic damping of Co2FeAl through an additional optical spin-transfer torque on the magnetic moment of Co2FeAl. Our results provide a valuable reference for manipulating spin-pumping and interfacial spin transport in FM/SC heterojunctions, showcasing the advantage of optical control of semiconductor photocarriers for the ultrafast manipulation of magnetic dynamics and interfacial spin transfer.
Collapse
Affiliation(s)
- Chongtao Kong
- 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
| | - Lin Song
- 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
| | - Xupeng 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
| | - 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
| | - Guodong Yuan
- 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
| |
Collapse
|
2
|
Lu Q, Yin S, Gao T, Qin W, Xie S, Qu F, Saxena A. Spin Transport Based on Exchange Coupling in Doped Organic Polymers. J Phys Chem Lett 2020; 11:1087-1092. [PMID: 31957440 DOI: 10.1021/acs.jpclett.9b03703] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We develop a spin diffusion theory based on the exchange mechanism among polarons to understand the organic pure spin current. It is demonstrated that the exchange coupling is strong enough to induce spin transport within the organic layer with impurity concentrations higher than 1018 cm-3. By calculating the inverse spin Hall voltage in an organic spin device, we predict that the voltage depends nonmonotonically on the impurity concentration of the organic material. By tuning the doping concentration, one can achieve a maximum inverse spin Hall voltage. Our results not only explain some recent experimental data but also inspire further experimental investigation on pure spin current in organic devices with variable impurity doping.
Collapse
Affiliation(s)
- Qiuxia Lu
- School of Physics, State Key Laboratory of Crystal Materials , Shandong University , Jinan 250100 , China
| | - Sun Yin
- School of Physics, State Key Laboratory of Crystal Materials , Shandong University , Jinan 250100 , China
| | - Teng Gao
- School of Physics, State Key Laboratory of Crystal Materials , Shandong University , Jinan 250100 , China
| | - Wei Qin
- School of Physics, State Key Laboratory of Crystal Materials , Shandong University , Jinan 250100 , China
| | - Shijie Xie
- School of Physics, State Key Laboratory of Crystal Materials , Shandong University , Jinan 250100 , China
| | - Fanyao Qu
- Instituto de F́ısica , Universidade de Braśılia , Braśılia DF 70919-970 , Brazil
| | - Avadh Saxena
- Theoretical Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
| |
Collapse
|
3
|
Ultrafast long-range spin-funneling in solution-processed Ruddlesden-Popper halide perovskites. Nat Commun 2019; 10:3456. [PMID: 31371709 PMCID: PMC6671992 DOI: 10.1038/s41467-019-11251-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 06/14/2019] [Indexed: 11/08/2022] Open
Abstract
Room-temperature spin-based electronics is the vision of spintronics. Presently, there are few suitable material systems. Herein, we reveal that solution-processed mixed-phase Ruddlesden-Popper perovskite thin-films transcend the challenges of phonon momentum-scattering that limits spin-transfer in conventional semiconductors. This highly disordered system exhibits a remarkable efficient ultrafast funneling of photoexcited spin-polarized excitons from two-dimensional (2D) to three-dimensional (3D) phases at room temperature. We attribute this efficient exciton relaxation pathway towards the lower energy states to originate from the energy transfer mediated by intermediate states. This process bypasses the omnipresent phonon momentum-scattering in typical semiconductors with stringent band dispersion, which causes the loss of spin information during thermalization. Film engineering using graded 2D/3D perovskites allows unidirectional out-of-plane spin-funneling over a thickness of ~600 nm. Our findings reveal an intriguing family of solution-processed perovskites with extraordinary spin-preserving energy transport properties that could reinvigorate the concepts of spin-information transfer.
Collapse
|
4
|
Cerqueira C, Qin JY, Dang H, Djeffal A, Le Breton JC, Hehn M, Rojas-Sanchez JC, Devaux X, Suire S, Migot S, Schieffer P, Mussot JG, Łaczkowski P, Anane A, Petit-Watelot S, Stoffel M, Mangin S, Liu Z, Cheng BW, Han XF, Jaffrès H, George JM, Lu Y. Evidence of Pure Spin-Current Generated by Spin Pumping in Interface-Localized States in Hybrid Metal-Silicon-Metal Vertical Structures. NANO LETTERS 2019; 19:90-99. [PMID: 30472859 DOI: 10.1021/acs.nanolett.8b03386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Due to the difficulty of growing high-quality semiconductors on ferromagnetic metals, the study of spin diffusion transport in Si was limited to lateral geometry devices. In this work, by using an ultrahigh-vacuum wafer-bonding technique, we have successfully fabricated metal-semiconductor-metal CoFeB/MgO/Si/Pt vertical structures. We hereby demonstrate pure spin-current injection and transport in the perpendicular current flow geometry over a distance larger than 2 μm in n-type Si at room temperature. In those experiments, a pure propagating spin current is generated via ferromagnetic resonance spin pumping and converted into a measurable voltage by using the inverse spin Hall effect occurring in the top Pt layer. A systematic study varying both Si and MgO thicknesses reveals the important role played by the localized states at the MgO-Si interface for the spin-current generation. Proximity effects involving indirect exchange interactions between the ferromagnet and the MgO-Si interface states appears to be a prerequisite to establishing the necessary out-of-equilibrium spin population in Si under the spin-pumping action.
Collapse
Affiliation(s)
- Carolina Cerqueira
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Sud, Université Paris-Saclay , 91767 , Palaiseau , France
- Laboratoire des Solides Irradiés, École Polytechnique, CNRS, CEA , Université Paris-Saclay , 91128 Palaiseau , France
| | - Jian Yin Qin
- Université de Lorraine , CNRS, Institut Jean Lamour, UMR 7198, campus ARTEM , 2 Allée André Guinier , 54011 Nancy , France
- Beijing National Laboratory of Condensed Matter Physics , Institute of Physics, University of Chinese Academy of Sciences , Beijing 100190 , PR China
| | - Huong Dang
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Sud, Université Paris-Saclay , 91767 , Palaiseau , France
| | - Abdelhak Djeffal
- Université de Lorraine , CNRS, Institut Jean Lamour, UMR 7198, campus ARTEM , 2 Allée André Guinier , 54011 Nancy , France
| | | | - Michel Hehn
- Université de Lorraine , CNRS, Institut Jean Lamour, UMR 7198, campus ARTEM , 2 Allée André Guinier , 54011 Nancy , France
| | - Juan-Carlos Rojas-Sanchez
- Université de Lorraine , CNRS, Institut Jean Lamour, UMR 7198, campus ARTEM , 2 Allée André Guinier , 54011 Nancy , France
| | - Xavier Devaux
- Université de Lorraine , CNRS, Institut Jean Lamour, UMR 7198, campus ARTEM , 2 Allée André Guinier , 54011 Nancy , France
| | - Stéphane Suire
- Université de Lorraine , CNRS, Institut Jean Lamour, UMR 7198, campus ARTEM , 2 Allée André Guinier , 54011 Nancy , France
| | - Sylvie Migot
- Université de Lorraine , CNRS, Institut Jean Lamour, UMR 7198, campus ARTEM , 2 Allée André Guinier , 54011 Nancy , France
| | - Philippe Schieffer
- Univ RennesCNRS, IPR (Institut de Physique de Rennes) - UMR 6251 , F-35000 Rennes , France
| | - Jean-Georges Mussot
- Université de Lorraine , CNRS, Institut Jean Lamour, UMR 7198, campus ARTEM , 2 Allée André Guinier , 54011 Nancy , France
| | - Piotr Łaczkowski
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Sud, Université Paris-Saclay , 91767 , Palaiseau , France
| | - Abdelmadjid Anane
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Sud, Université Paris-Saclay , 91767 , Palaiseau , France
| | - Sebastien Petit-Watelot
- Université de Lorraine , CNRS, Institut Jean Lamour, UMR 7198, campus ARTEM , 2 Allée André Guinier , 54011 Nancy , France
| | - Mathieu Stoffel
- Université de Lorraine , CNRS, Institut Jean Lamour, UMR 7198, campus ARTEM , 2 Allée André Guinier , 54011 Nancy , France
| | - Stéphane Mangin
- Université de Lorraine , CNRS, Institut Jean Lamour, UMR 7198, campus ARTEM , 2 Allée André Guinier , 54011 Nancy , France
| | - Zhi Liu
- State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Center of Materials Science and Optoelectronics Engineering , University of Chinese Academy of Sciences Chinese Academy of Sciences , Beijing 100083 , PR China
| | - Bu Wen Cheng
- State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Center of Materials Science and Optoelectronics Engineering , University of Chinese Academy of Sciences Chinese Academy of Sciences , Beijing 100083 , PR China
| | - Xiu Feng Han
- Beijing National Laboratory of Condensed Matter Physics , Institute of Physics, University of Chinese Academy of Sciences , Beijing 100190 , PR China
| | - Henri Jaffrès
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Sud, Université Paris-Saclay , 91767 , Palaiseau , France
| | - Jean-Marie George
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Sud, Université Paris-Saclay , 91767 , Palaiseau , France
| | - Yuan Lu
- Université de Lorraine , CNRS, Institut Jean Lamour, UMR 7198, campus ARTEM , 2 Allée André Guinier , 54011 Nancy , France
| |
Collapse
|
5
|
Yamada M, Fujita Y, Yamada S, Sawano K, Hamaya K. Spin Absorption Effect at Ferromagnet/Ge Schottky-Tunnel Contacts. MATERIALS 2018; 11:ma11010150. [PMID: 29342078 PMCID: PMC5793648 DOI: 10.3390/ma11010150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Revised: 01/10/2018] [Accepted: 01/15/2018] [Indexed: 12/04/2022]
Abstract
We study the influence of the junction size in ferromagnet (FM)/semiconductor (SC) contacts on four-terminal nonlocal spin signals in SC-based lateral spin-valve (LSV) structures. When we use FM/Ge Schottky-tunnel junctions with relatively low resistance-area products, the magnitude of the nonlocal spin signal depends clearly on the junction size, indicating the presence of the spin absorption effect at the spin-injector contact. The temperature-dependent spin signal can also be affected by the spin absorption effect. For SC spintronic applications with a low parasitic resistance, we should consider the influence of the spin absorption on the spin-transport signals in SC-based device structures.
Collapse
Affiliation(s)
- Michihiro Yamada
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka 560-8531, Japan.
| | - Yuichi Fujita
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka 560-8531, Japan.
| | - Shinya Yamada
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka 560-8531, Japan.
- Center for Spintronics Research Network, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka 560-8531, Japan.
| | - Kentarou Sawano
- Advanced Research Laboratories, Tokyo City University, 8-15-1 Todoroki, Tokyo 158-0082, Japan.
| | - Kohei Hamaya
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka 560-8531, Japan.
- Center for Spintronics Research Network, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka 560-8531, Japan.
| |
Collapse
|
6
|
Ohshima R, Ando Y, Matsuzaki K, Susaki T, Weiler M, Klingler S, Huebl H, Shikoh E, Shinjo T, Goennenwein STB, Shiraishi M. Strong evidence for d-electron spin transport at room temperature at a LaAlO 3/SrTiO 3 interface. NATURE MATERIALS 2017; 16:609-614. [PMID: 28191896 DOI: 10.1038/nmat4857] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 01/16/2017] [Indexed: 06/06/2023]
Abstract
A d-orbital electron has an anisotropic electron orbital and is a source of magnetism. The realization of a two-dimensional electron gas (2DEG) embedded at a LaAlO3/SrTiO3 interface surprised researchers in materials and physical sciences because the 2DEG consists of 3d-electrons of Ti with extraordinarily large carrier mobility, even in the insulating oxide heterostructure. To date, a wide variety of physical phenomena, such as ferromagnetism and the quantum Hall effect, have been discovered in this 2DEG system, demonstrating the ability of d-electron 2DEG systems to provide a material platform for the study of interesting physics. However, because of both ferromagnetism and the Rashba field, long-range spin transport and the exploitation of spintronics functions have been believed difficult to implement in d-electron 2DEG systems. Here, we report the experimental demonstration of room-temperature spin transport in a d-electron-based 2DEG at a LaAlO3/SrTiO3 interface, where the spin relaxation length is about 300 nm. Our finding, which counters the conventional understandings of d-electron 2DEGs, highlights the spin-functionality of conductive oxide systems and opens the field of d-electron spintronics.
Collapse
Affiliation(s)
- Ryo Ohshima
- Department of Electronic Science and Engineering, Kyoto University, 615-8510 Kyoto, Japan
- Graduate School of Engineering Science, Osaka University, 560-8531 Toyonaka, Japan
| | - Yuichiro Ando
- Department of Electronic Science and Engineering, Kyoto University, 615-8510 Kyoto, Japan
| | - Kosuke Matsuzaki
- Secure Materials Center, Materials and Structures Laboratories, Tokyo Institute of Technology, 226-8503 Yokohama, Japan
| | - Tomofumi Susaki
- Secure Materials Center, Materials and Structures Laboratories, Tokyo Institute of Technology, 226-8503 Yokohama, Japan
| | - Mathias Weiler
- Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany
- Physik-Department, Technische Universität München, 85748 Garching, Germany
| | - Stefan Klingler
- Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany
- Physik-Department, Technische Universität München, 85748 Garching, Germany
| | - Hans Huebl
- Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany
- Physik-Department, Technische Universität München, 85748 Garching, Germany
- Nanosystems Initiative Munich, 80799 München, Germany
| | - Eiji Shikoh
- Graduate School of Engineering, Osaka City University, 558-8585 Osaka, Japan
| | - Teruya Shinjo
- Department of Electronic Science and Engineering, Kyoto University, 615-8510 Kyoto, Japan
| | - Sebastian T B Goennenwein
- Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany
- Physik-Department, Technische Universität München, 85748 Garching, Germany
- Nanosystems Initiative Munich, 80799 München, Germany
| | - Masashi Shiraishi
- Department of Electronic Science and Engineering, Kyoto University, 615-8510 Kyoto, Japan
| |
Collapse
|
7
|
Bottegoni F, Zucchetti C, Dal Conte S, Frigerio J, Carpene E, Vergnaud C, Jamet M, Isella G, Ciccacci F, Cerullo G, Finazzi M. Spin-Hall Voltage over a Large Length Scale in Bulk Germanium. PHYSICAL REVIEW LETTERS 2017; 118:167402. [PMID: 28474919 DOI: 10.1103/physrevlett.118.167402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Indexed: 06/07/2023]
Abstract
We exploit the spin-Hall effect to generate a uniform pure spin current in an epitaxial n-doped Ge channel, and we detect the electrically induced spin accumulation, transverse to the injected charge current density, with polar magneto-optical Kerr microscopy at a low temperature. We show that a large spin density up to 400 μm^{-3} can be achieved at the edges of the 100-μm-wide Ge channel for an applied electric field lower than 5 mV/μm. We find that the spin density linearly decreases toward the center of the Ge bar, due to the large spin diffusion length, and such a decay is much slower than the exponential one observed in III-V semiconductors, allowing very large spin accumulations over a length scale of tens of micrometers. This lays the foundation for multiterminal spintronic devices, where different spin voltages can be exploited as inputs for magnetologic gates on the same Ge platform.
Collapse
Affiliation(s)
- F Bottegoni
- LNESS-Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - C Zucchetti
- LNESS-Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - S Dal Conte
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - J Frigerio
- LNESS-Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - E Carpene
- IFN-CNR, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - C Vergnaud
- Université Grenoble Alpes, INAC-SPINTEC, F38000 Grenoble, France
- CEA-INAC-SPINTEC, F38054 Grenoble, France
| | - M Jamet
- Université Grenoble Alpes, INAC-SPINTEC, F38000 Grenoble, France
- CEA-INAC-SPINTEC, F38054 Grenoble, France
| | - G Isella
- LNESS-Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - F Ciccacci
- LNESS-Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - G Cerullo
- IFN-CNR, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - M Finazzi
- LNESS-Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| |
Collapse
|
8
|
|
9
|
Rortais F, Oyarzún S, Bottegoni F, Rojas-Sánchez JC, Laczkowski P, Ferrari A, Vergnaud C, Ducruet C, Beigné C, Reyren N, Marty A, Attané JP, Vila L, Gambarelli S, Widiez J, Ciccacci F, Jaffrès H, George JM, Jamet M. Spin transport in p-type germanium. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:165801. [PMID: 26988255 DOI: 10.1088/0953-8984/28/16/165801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We report on the spin transport properties in p-doped germanium (Ge-p) using low temperature magnetoresistance measurements, electrical spin injection from a ferromagnetic metal and the spin pumping-inverse spin Hall effect method. Electrical spin injection is carried out using three-terminal measurements and the Hanle effect. In the 2-20 K temperature range, weak antilocalization and the Hanle effect provide the same spin lifetime in the germanium valence band (≈1 ps) in agreement with predicted values and previous optical measurements. These results, combined with dynamical spin injection by spin pumping and the inverse spin Hall effect, demonstrate successful spin accumulation in Ge. We also estimate the spin Hall angle θ(SHE) in Ge-p (6-7 x 10(-4) at room temperature, pointing out the essential role of ionized impurities in spin dependent scattering.
Collapse
Affiliation(s)
- F Rortais
- Université Grenoble Alpes, INAC-SPINTEC, F-38000 Grenoble, France. CEA, INAC-SPINTEC, F-38000 Grenoble, France. CNRS, INAC-SPINTEC, F-38000 Grenoble, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Dushenko S, Ago H, Kawahara K, Tsuda T, Kuwabata S, Takenobu T, Shinjo T, Ando Y, Shiraishi M. Gate-Tunable Spin-Charge Conversion and the Role of Spin-Orbit Interaction in Graphene. PHYSICAL REVIEW LETTERS 2016; 116:166102. [PMID: 27152812 DOI: 10.1103/physrevlett.116.166102] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Indexed: 05/22/2023]
Abstract
The small spin-orbit interaction of carbon atoms in graphene promises a long spin diffusion length and the potential to create a spin field-effect transistor. However, for this reason, graphene was largely overlooked as a possible spin-charge conversion material. We report electric gate tuning of the spin-charge conversion voltage signal in single-layer graphene. Using spin pumping from an yttrium iron garnet ferrimagnetic insulator and ionic liquid top gate, we determined that the inverse spin Hall effect is the dominant spin-charge conversion mechanism in single-layer graphene. From the gate dependence of the electromotive force we showed the dominance of the intrinsic over Rashba spin-orbit interaction, a long-standing question in graphene research.
Collapse
Affiliation(s)
- S Dushenko
- Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan
- Department of Electronic Science and Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - H Ago
- Institute for Material Chemistry and Engineering, Kyushu University, Fukuoka 816-8508, Japan
| | - K Kawahara
- Institute for Material Chemistry and Engineering, Kyushu University, Fukuoka 816-8508, Japan
| | - T Tsuda
- Graduate School of Engineering, Osaka University, Suita 565-0871, Japan
| | - S Kuwabata
- Graduate School of Engineering, Osaka University, Suita 565-0871, Japan
| | - T Takenobu
- School of Advanced Science and Engineering, Waseda University, Tokyo 169-8555, Japan
| | - T Shinjo
- Department of Electronic Science and Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Y Ando
- Department of Electronic Science and Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - M Shiraishi
- Department of Electronic Science and Engineering, Kyoto University, Kyoto 615-8510, Japan
| |
Collapse
|
11
|
Zhao J, Zeng H. Chemically functionalized germanene for spintronic devices: a first-principles study. Phys Chem Chem Phys 2016; 18:9809-15. [DOI: 10.1039/c5cp08055j] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have carried out first-principles calculations to explore various chemically functionalized germanene nanomaterials as two-dimensional spintronic devices.
Collapse
Affiliation(s)
- Jun Zhao
- School of Chemistry and Chemical Engineering
- Collaborative Innovation Center of Advanced Microstructures
- Nanjing University
- Nanjing 210093
- China
| | - Hui Zeng
- School of Chemistry and Chemical Engineering
- Collaborative Innovation Center of Advanced Microstructures
- Nanjing University
- Nanjing 210093
- China
| |
Collapse
|
12
|
Sigillito AJ, Jock RM, Tyryshkin AM, Beeman JW, Haller EE, Itoh KM, Lyon SA. Electron Spin Coherence of Shallow Donors in Natural and Isotopically Enriched Germanium. PHYSICAL REVIEW LETTERS 2015; 115:247601. [PMID: 26705654 DOI: 10.1103/physrevlett.115.247601] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Indexed: 06/05/2023]
Abstract
Germanium is a widely used material for electronic and optoelectronic devices and recently it has become an important material for spintronics and quantum computing applications. Donor spins in silicon have been shown to support very long coherence times (T_{2}) when the host material is isotopically enriched to remove any magnetic nuclei. Germanium also has nonmagnetic isotopes so it is expected to support long T_{2}'s while offering some new properties. Compared to Si, Ge has a strong spin-orbit coupling, large electron wave function, high mobility, and highly anisotropic conduction band valleys which will all give rise to new physics. In this Letter, the first pulsed electron spin resonance measurements of T_{2} and the spin-lattice relaxation (T_{1}) times for ^{75}As and ^{31}P donors in natural and isotopically enriched germanium are presented. We compare samples with various levels of isotopic enrichment and find that spectral diffusion due to ^{73}Ge nuclear spins limits the coherence in samples with significant amounts of ^{73}Ge. For the most highly enriched samples, we find that T_{1} limits T_{2} to T_{2}=2T_{1}. We report an anisotropy in T_{1} and the ensemble linewidths for magnetic fields oriented along different crystal axes but do not resolve any angular dependence to the spectral-diffusion-limited T_{2} in samples with ^{73}Ge.
Collapse
Affiliation(s)
- A J Sigillito
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - R M Jock
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - A M Tyryshkin
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - J W Beeman
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - E E Haller
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
| | - K M Itoh
- School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohuku-ku, Yokohama 223-8522, Japan
| | - S A Lyon
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
| |
Collapse
|
13
|
Pu Y, Odenthal PM, Adur R, Beardsley J, Swartz AG, Pelekhov DV, Flatté ME, Kawakami RK, Pelz J, Hammel PC, Johnston-Halperin E. Ferromagnetic Resonance Spin Pumping and Electrical Spin Injection in Silicon-Based Metal-Oxide-Semiconductor Heterostructures. PHYSICAL REVIEW LETTERS 2015; 115:246602. [PMID: 26705647 DOI: 10.1103/physrevlett.115.246602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Indexed: 06/05/2023]
Abstract
We present the measurement of ferromagnetic resonance (FMR-)driven spin pumping and three-terminal electrical spin injection within the same silicon-based device. Both effects manifest in a dc spin accumulation voltage V_{s} that is suppressed as an applied field is rotated to the out-of-plane direction, i.e., the oblique Hanle geometry. Comparison of V_{s} between these two spin injection mechanisms reveals an anomalously strong suppression of FMR-driven spin pumping with increasing out-of-plane field H_{app}^{z}. We propose that the presence of the large ac component to the spin current generated by the spin pumping approach, expected to exceed the dc value by 2 orders of magnitude, is the origin of this discrepancy through its influence on the spin dynamics at the oxide-silicon interface. This convolution, wherein the dynamics of both the injector and the interface play a significant role in the spin accumulation, represents a new regime for spin injection that is not well described by existing models of either FMR-driven spin pumping or electrical spin injection.
Collapse
Affiliation(s)
- Y Pu
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - P M Odenthal
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
| | - R Adur
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - J Beardsley
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - A G Swartz
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
| | - D V Pelekhov
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - M E Flatté
- Departent of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, USA
| | - R K Kawakami
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
| | - J Pelz
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - P C Hammel
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | | |
Collapse
|