Giant spin splitting and 0-pi Josephson transitions from the Edelstein effect in quantum spin Hall insulators

Article

关键词: SUPERCONDUCTORS;    SPINTRONICS;    JUNCTIONS;    STATES;   

DOI  :  10.1103/PhysRevB.95.245407

来源: SCIE

【 摘 要 】

Hybrid structures of quantum spin Hall insulators (QSHIs) and superconductors (Ss) present a unique opportunity to access dissipationless topological states of matter, which, however, is frequently hindered by the lack of control over the spin polarization in QSHIs. We propose a very efficient spin-polarization mechanism based on the magnetoelectric (Edelstein) effect in superconducting QSHI structures. It acts akin to the Zeeman splitting in an external magnetic field, but with an effective g factor of order of 1000, resulting in an unprecedented spin splitting effect. It allows a magnetic control of the QSHI/S hybrids without destroying superconductivity. As an example, we demonstrate a recurrent crossover from Phi(0)-to (Phi(0)/2)-periodic oscillations of the Josephson current in an rf superconducting quantum interference device (Phi(0) = h/2e is the magnetic flux quantum). The predicted period halving is a strikingmanifestation of 0-pi Josephson transitions with a superharmonic pi-periodic current-phase relationship at the transition. Such controllable 0-pi transitions may offer new perspectives for dissipationless spintronics and engineering flux qubits.

【 授权许可】

Free