Dynamic Magnetoelectric Effect in Ferromagnet-Superconductor Tunnel Junctions

TL;DR

This paper investigates how magnetization precession in ferromagnet-superconductor tunnel junctions induces a voltage that varies with frequency and superconducting correlations, revealing potential for low-temperature magnetic spectroscopy.

Contribution

It introduces the study of the dynamic magnetoelectric effect in ferromagnet-superconductor tunnel junctions, highlighting the influence of superconducting correlations on induced voltage behavior.

Findings

Voltage varies nonmonotonically with precessional frequency.

Superconducting correlations significantly enhance the induced voltage.

Voltage peaks when the frequency matches the superconducting gap energy.

Abstract

We study the magnetization dynamics in a ferromagnet-insulator-superconductor tunnel junction and the associated buildup of the electrical polarization. We show that for an open circuit, the induced voltage varies strongly and nonmonotonically with the precessional frequency, and can be enhanced significantly by the superconducting correlations. For frequencies much smaller or much larger than the superconducting gap, the voltage drops to zero, while when these two energy scales are comparable, the voltage is peaked at a value determined by the driving frequency. We comment on the potential utilization of the effect for the low-temperature spatially-resolved spectroscopy of magnetic dynamics.