Tunable Planar Josephson Junctions Driven by Time-Dependent Spin-Orbit Coupling

Abstract

Integrating conventional superconductors with common III-V semiconductors provides a versatile platform to implement tunable Josephson junctions (JJs) and their applications. We propose that with gate-controlled time-dependent spin-orbit coupling, it is possible to strongly modify the currentphase relations and Josephson energy and provide a mechanism to drive the JJ dynamics, even in the absence of any bias current. We show that the transition between stable phases is realized with a simple linear change in the strength of the spin-orbit coupling, while the transition rate can exceed the gate-induced electric field GHz changes by an order of magnitude. The resulting interplay between the constant effective magnetic field and changing spin-orbit coupling has direct implications for superconducting spintronics, controlling Majorana bound states, and emerging qubits. We argue that topological superconductivity, sought for fault-tolerant quantum computing, offers simpler applications in superconducting electronics and spintronics.

Superconductor/Ferromagnet Heterostructures: A Platform for Superconducting Spintronics and Quantum Computation

“…Looking forward, we expect a direct connection of experimental investigation of the spin-triplet SC and p-wave SC in SC/FM heterostructures by optimizing device structures to attain ballistic transport [147] or using the topological FM [148][149][150]. Furthermore, the interaction of superconductivity, ferromagnetism, and topology might also give rise to additional novel phenomena, such as the Josephson diode effect [151,152], which was also previously seen in the studies of Al/InAs 2DEG junctions that could support topological superconductivity [153,154] and can have interesting time-dependent manifestations [155]. Furthemore, vortex diode effect has also been explored in SC/FM heterostructures very recently [156], which shows the potential to realize the on-chip microwave filter for future superconducting quantum circuit application.…”

“…[148][149][150] Furthermore, the interaction of superconductivity, ferromagnetism, and topology might also give rise to additional novel phenomena, such as the Josephson diode effect, [151,152] which was also previously seen in the studies of Al/InAs 2DEG junctions that could support topological superconductivity [153,154] and can have interesting time-dependent manifestations. [155] Furthermore, vortex diode effect has also been explored in SC/FM heterostructures very recently, [156] which shows the potential to realize the on-chip microwave filter for future superconducting quantum circuit application. The realization of FMR induced spin-triplet SC [75,76] will be not only a new experimental strategy to realize spin-triplet SC, but also a foundation for the coupling between microwave photon and SC/FM systems.…”