Inverse Spin Hall Effect in Electron Beam Evaporated Topological Insulator Bi2Se3 Thin Film
Braj B Singh et al.
physica status solidi (RRL)–Rapid Research Letters 13 (3), 2018, 1800492
Spintronics exploiting pure spin current in ferromagnetic (FM)/heavy metals (HM) is a subject of intense research. Topological insulators having spin momentum locked surface states exhibit high spin–orbit coupling and thus possess a huge potential to replace the HM like Pt, Ta, W, etc. In this context, the spin pumping phenomenon in Bi2Se3/CoFeB bilayers has been investigated. Bi2Se3 thin films are fabricated by electron beam evaporation method on Si (100) substrate. In order to confirm the topological nature of Bi2Se3, low temperature magnetotransport measurement on a 30 nm thick Bi2Se3 film which shows 10% magnetoresistance (MR) at 1.5 K has been performed. A linear increase in MR with applied magnetic field indicates the presence of spin momentum‐locked surface states. A voltage has been measured at room temperature to quantify the spin pumping which is generated via inverse spin Hall effect (ISHE). For the separation of spin rectification effects mainly produced by the FM CoFeB layer, in plane angular dependence of the dc voltage with respect to applied magnetic field has been measured. Our analysis reveals that spin pumping induced ISHE is the dominant contribution in the measured voltage.
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Prof. Dr. Subhankar Bedanta
Professor in Physics
Chief-Coordinator of Centre for Interdisciplinary Sciences (CIS), NISER
Laboratory for Nanomagnetism and Magnetic Materials (LNMM)
National Institute of Science Education and Research
Funding and projects
Our major funding is supported via
Department of Atomic Energy (DAE), Govt. of India, Rs 13.6 Crores in 12th plan budget
Our laboratory is supported via DST-SERB, DST-Nanomission and DST in form of the following projects:
1. Superferromagnetism in nanoparticles systems (Completed)
DST Nanomission- Grant ~ Rs 50 lakhs
2. Inter-layer coupling in ferromagnetic/non-magnetic multilayers (Completed)
DST-DAAD bilateral project- 2012 to 2014
3. Engineering magnetic domains in Co antidote arrays (Completed)
DST-SERB – Grant ~ Rs. 50 lakhs
4. Electric field induced spin wave spectra in multiferroic antidot lattice arrays
India-Poland bilateral proposal via DST – Grant ~ Rs. 17 lakhs (Completed)
5. Ferromagnetic-semiconductor heterostructures for magnetic field sensing and optoelectronics applications (Completed)
DST Nanomission- Grant ~ Rs 62.5 lakhs
6. Creating magnetic interface in non-magnetic organic thin films for spintronic applications (Completed)
DST-SERB- Grant~ Rs 60.75 lakhs
7. Tuning the interfacial Dzyaloshinskii-Moriya interaction in ultrathin
magnetic films: toward the stabilization of skyrmions in spintronics devices
(Completed)
Indo-French bilateral project in sharing where, CEFIPRA-Grant for NISER side- Rs 73.2 lakhs and the total budget is Rs 135 lakhs
8. Royal Society funding: Bilateral project supported by Royal Society, UK, for research on organic spontronics between the group of Prof. Bedanta and Prof. Del Atkinson.(Continuing)
9. Indo-Japan project to organize conference on magnetism on nanoscale (IJWMN - 2022)
10. DAE Project (2021-2024)
11. Spin to charge conversion in ferromagnet/non-magnet systems through spin pumping by inverse spin Hall effect method (Continuing)
DST-SERB grant- Rs. 32 lakhs
12. Harnessing pure spin current by tailoring molecular spinterface
In this project, the PI is Dr. C. Murapaka from IIT Hyderabad and Dr. S. Bedanta is the principal collaborator (PC)
Acknowledgment for other fundings:
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Newton funds, UK and NFFA-Europe
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DST-neutron and synchrotron funds to provide financial support for performing neutron and synchrotron experiments at large scale neutron and synchrotron facilities like ALBA synchrotron, Barcelona, Spain
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ISIS neutron source at Rutherford Appleton Laboratory, Oxford, UK; MLZ neutron facility, Munich, Germany; Diamond Light Source, UK, etc.