Long-range spin-polarized Josephson effect in ballistic S/F/S junctions with precessing magnetization

TL;DR

This paper develops a theory for ballistic S/F/S junctions with precessing magnetization, revealing long-range superconducting correlations and a switchable Josephson current influenced by magnetization dynamics.

Contribution

It introduces a detailed theoretical framework for understanding how precessing magnetization induces long-range equal-spin superconducting correlations in ballistic junctions.

Findings

Precessing magnetization generates long-range equal-spin superconducting correlations.

The current-phase relationship becomes strongly non-sinusoidal at large precession angles.

Magnetization precession can switch the junction between 'off' and 'on' states in half-metallic ferromagnets.

Abstract

We present a theory of ballistic N/F/S and S/F/S junctions with a uniformly precessing magnetization, which generates long-range equal-spin superconducting correlations [Takahashi et al., Phys. Rev. Lett. 99, 057003 (2007), Houzet, Phys. Rev. Lett. 101, 057009 (2008)]. The non-equilibrium distribution of Andreev bound states leads to a strongly non-sinusoidal current-phase relationship for large precession angles. We derive detailed results for ballistic junctions involving partially and fully polarized ferromagnets. In the fully polarized half-metal limit, the magnetization precession switches the junction from an "off" state with vanishing subgap current to an "on" state with finite Andreev conductance and finite Josephson current.