Magnetic resonance in a singlet-triplet Josephson junction

TL;DR

This paper investigates a Josephson junction between s-wave and p_x-wave superconductors, revealing a spontaneous magnetization and controllable Rabi oscillations via magnetic fields, with potential applications in quantum control.

Contribution

It introduces the study of a singlet-triplet Josephson junction with novel magnetic and quantum control phenomena, including phase-dependent Rabi oscillations and spin selection rules.

Findings

Spontaneous magnetization in the junction's equilibrium state.

Magnetic field induces Rabi oscillations in Andreev levels.

Resonance observed in the current-phase relation depending on magnetic field and phase difference.

Abstract

We study a singlet-triplet Josephson junction between a conventional s-wave superconductor and an unconventional p$_{\rm x}$-wave superconductor. The Andreev spectrum of the junction yields a spontaneous magnetization in equilibrium. This allows manipulating the occupation of the Andreev levels using an ac Zeeman field. The induced Rabi oscillations manifest themselves as a resonance in the current-phase relation. For a circularly polarized magnetic field, we find a spin selection rule, yielding Rabi oscillations only in a certain interval of the superconducting phase difference.