Locking of magnetization and Josephson oscillations at ferromagnetic resonance in $\varphi_0$ junction under external radiation

TL;DR

This paper investigates how external electromagnetic radiation can lock magnetic precession and Josephson oscillations in a $\

Contribution

It introduces a method to control magnetic precession amplitude and frequency in $\\varphi_0$ junctions via external radiation, revealing new locking phenomena and effects of spin-orbit coupling.

Findings

Locking of magnetic precession by radiation at ferromagnetic resonance.

Appearance of additional locking steps in strong spin-orbit coupling junctions.

Control over amplitude and frequency of magnetic oscillations.

Abstract

We demonstrate the locking by external electromagnetic radiation of magnetic precession in the $ \varphi_0 $ Josephson junction through Josephson oscillations in the region of ferromagnetic resonance. This leads to a step in the dependence of the magnetization on the bias current, the position of which is determined by the radiation frequency and the shape of the resonance curve. In junctions with a strong spin-orbit coupling, states with negative differential resistance appear on the IV-characteristic, resulting in an additional locking step. A detailed study of the time dependence of voltage and magnetization and their Fourier transforms shows that the corresponding oscillations have the same frequency as the oscillations at the first step, but they have a different amplitude and different dependence on the radiation frequency. This makes it possible to control not only the frequency, but also the amplitude of the magnetic precession in the locking region. It opens up unique perspectives for the control and manipulation of magnetic moment in hybrid systems such as anomalous Josephson junctions.