Collective magnetic and plasma excitations in Josephson $\psi$ junctions

TL;DR

This paper demonstrates that Josephson ψ junctions with half-metallic links exhibit coupled magnetic and plasma excitations, leading to controllable magnetization reversal, anomalies in current-voltage behavior, and new magnetic anisotropy effects.

Contribution

It introduces the coupling of magnetic and plasma modes in long-wavelength limit Josephson ψ junctions with half-metallic links, enabling magnetic control via current pulses.

Findings

Coupling between magnetic and plasma modes observed in ψ junctions.

Magnetization reversal controllable by d.c. current pulses.

Anomalies in current-voltage characteristics linked to collective excitations.

Abstract

We show that Josephson $\psi$ junctions with the half-metallic (HM) weak link coupled to the superconducting (S) electrodes through the ferromagnetic (F) layers host collective excitations of magnetic moment and the Josephson phase. This results in the shift of the ferromagnetic resonance frequency, anomalies in the current-voltage characteristics and the appearance of additional magnetic anisotropy in the F layers. In contrast to the previously studied S/F/S junctions, the coupling between magnetic and plasma modes emerges even in the long-wavelength limit. Such coupling is shown to enable the controllable magnetization reversal in the F layer governed by the d.c. current pulse which provides the effective mechanism for magnetic moment manipulation in the devices of superconducting spintronics.