Anderson-Higgs mass of magnons in superconductor/ferromagnet/superconductor systems

TL;DR

This paper demonstrates that the Anderson-Higgs mechanism influences magnon spectra in superconductor/ferromagnet/superconductor systems, explaining experimental observations and enabling control over magnon properties for magnonic applications.

Contribution

It reveals the spectroscopic manifestation of the Anderson-Higgs mass in magnon spectra and explains recent experimental ferromagnetic resonance shifts in multilayer systems.

Findings

The Anderson-Higgs mass determines the magnon spectrum gap.

Recent experiments observed a spontaneous ferromagnetic resonance shift.

The theory enables control over magnon spectral gap and group velocity.

Abstract

Anderson-Higgs mechanism of mass generation is a generic concept in high-energy and condensed matter physics. It shows up through the Meissner effect providing the expulsion of static and low-frequency magnetic fields from superconductors. However, it does not affect propagating electromagnetic waves with a spectrum gap determined by the plasma frequency, which is too large to be sensitive to the superconducting transition. Here we demonstrate the spectroscopic manifestation of the Anderson-Higgs mass, showing that it determines the spectrum gap of magnons in superconductor/ferromagnet/superconductor multilayers. Moreover, we show that this effect has been observed in recent experiments as a spontaneous ferromagnetic resonance frequency shift in such systems. Our theory explains many unusual experimental features and suggests effective controls over the magnon spectrum with tunable spectral gap and group-velocity reversal. These findings pave the way to a wide range of advanced functionalities for possible applications in magnonics.