1. spin-orbit splitting of andreev states in josephson weak links

Sunghun Park

Universidad Autónoma de Madrid, Spain

17 February 2022 Thu 4 pm

                                      IBS Center for Theoretical Physics of Complex Systems (PCS), Administrative Office (B349), Theory Wing, 3rd floor

                                      Expo-ro 55, Yuseong-gu, Daejeon, South Korea, 34126 Tel: +82-42-878-8633                     

Finding qubit with long coherence times and high controllability is a long-standing goal in quantum information science and condensed matter physics. Spin degree of freedom confined by a superconducting gap has been considered as a new resource for such qubits. In this talk, I will present our recent theoretical and experimental studies on spin-split Andreev states in a semiconducting nanowire Josephson weak link performed in collaboration with an experimental group. I provide a theoretical model for the weak link which takes into account Rashba spin-orbit coupling in the nanowire containing several transverse subbands, identifying the spin-orbit splitting of Andreev states. The theory allows us to understand the response of the microwave resonator coupled to the weak link observed in circuit quantum electrodynamics experiments. Finally, I discuss about the possible uses of the Andreev states as a new qubit.