Light‐Induced Giant Rashba Spin–Orbit Coupling at Superconducting KTaO<sub>3</sub>(110) Heterointerfaces
Yulin Gan, Fazhi Yang, Lingyuan Kong, Xuejiao Chen, Hao Xu, Jin Zhao, Gang Li, Yuchen Zhao, Lei Yan, Zhicheng Zhong, Yunzhong Chen, Hong Ding
Abstract
Abstract The 2D electron system (2DES) at the KTaO 3 surface or heterointerface with 5d orbitals hosts extraordinary physical properties, including a stronger Rashba spin–orbit coupling (RSOC), higher superconducting transition temperature, and potential of topological superconductivity. Herein, a huge enhancement of RSOC under light illumination achieved at a superconducting amorphous‐Hf 0.5 Zr 0.5 O 2 /KTaO 3 (110) heterointerfaces is reported. The superconducting transition is observed with T c = 0.62 K and the temperature‐dependent upper critical field reveals the interaction between spin–orbit scattering and superconductivity. A strong RSOC with B so = 1.9 T is revealed by weak antilocalization in the normal state, which undergoes sevenfold enhancement under light illumination. Furthermore, RSOC strength develops a dome‐shaped dependence of carrier density with the maximum of B so = 12.6 T achieved near the Lifshitz transition point n c ≈ 4.1 × 10 13 cm −2 . The highly tunable giant RSOC at KTaO 3 (110)‐based superconducting interfaces show great potential for spintronics.