Enhanced Spin-to-Charge Conversion Efficiency in Ultrathin Bi2Se3 Observed by Spintronic Terahertz Spectroscopy
Source abstract
Abstract
Owing to their remarkable spin–charge conversion (SCC) efficiency, topological insulators (TIs) are the most attractive candidates for spin–orbit torque generators. The simple method of enhancing SCC efficiency is to reduce the thickness of TI films to minimize the trivial bulk contribution. However, when the thickness reaches the ultrathin regime, the SCC efficiency decreases owing to intersurface hybridization. To overcome these contrary effects, we induced dehybridization of the ultrathin TI film by breaking the inversion symmetry between surfaces. For the TI film grown on an oxygen-deficient transition-metal oxide, the unbonded transition-metal d-orbitals affected only the bottom surface, resulting in asymmetric surface band structures. Spintronic terahertz emission spectroscopy, an emerging tool for investigating the SCC characteristics, revealed that the resulting SCC efficiency in symmetry-broken ultrathin Bi2Se3 was enhanced by up to ∼2.4 times.
Source: openalex_inverted_index · Quality: baseline
Research context
OpenAlex topics: Topological Materials and Phenomena · Magnetic properties of thin films · Atomic and Subatomic Physics Research
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
Department of Physics, Yonsei University, Seoul 03722, Republic of Korea
Division of Physics and Semiconductor Science, Dongguk University, Seoul 04620, Republic of Korea
YUHS-KRIBB, Medical Convergence Research Institute, College of Medicine, Yonsei University, Seoul 03722, Republic of Korea
Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon 16419, Republic of Korea
Department of Physics, School of Engineering, University of Petroleum and Energy Studies, Dehradun 248007, Uttarakhand, India
Department of Materials Science and Engineering, Yonsei University, Seoul 03722, Republic of Korea
Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
Funding
National Research Foundation of Korea
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