[19p-Z19-1~7] 10.4 Semiconductor spintronics, superconductor, multiferroics

▲ [19p-Z19-3] Evaluation of Spin-Charge Conversion at Nonmagnetic Metal and Topological Insulator Contact Using Spin Valve Structure

〇Taiki Nishijima¹, Yuichiro Ando¹, Ei Shigematsu¹, Ryo Ohshima¹, Liu Enlong², Yang Dongsheng², Hyunsoo Yang², Masashi Shiraishi¹ (1.Kyoto Univ., 2.National University of Singapore)

Keywords:Topological Insulator, Spin Valve, Spin-charge Conversion

Topological insulator (TI) is an attracting material as a host of spin and charge (S-C) interconversion. However, main stage of S-C conversion with TIs has been ferromagnetic metal (FM) and TI contact. In fact, spin to charge conversion efficiencies were varied among reports. In this study, we focused on S-C conversion at nonmagnetic metal (NM) and TI contact.
We fabricated three lateral spin valves (LSVs), Ref.1, Ref.2 and w/ TI. We used Py, Cu and Bi₂Se₃ as FM, NM and TI, respectively. As a result of non-local four terminal measurement (NL4T), the NL4T resistance of Ref.1 and w/ TI were 1.59 mΩ and 1.12 mΩ, indicating spin absorption to the TI stripe. Second, spin to charge conversion was tested. The sign of S-C conversion resistance (R_S-C) changes due to the reversal of the direction of accumulated spin in NM channel, and ΔR_S-C was 0.04 mΩ. This result successfully demonstrates the S-C conversion at NM/TI area. Next, charge to spin conversion was also successfully demonstrated.