Harnessing Ultraconfined Graphene Plasmons to Probe the Electrodynamics of Superconductors

TL;DR

This paper demonstrates how ultraconfined graphene plasmons can be used with near-field optics to observe the Higgs mode in superconductors, revealing new ways to study superconductor electrodynamics.

Contribution

It introduces a novel method using graphene plasmons and quantum emitters to make the Higgs mode observable via near-field optics, which was previously difficult to detect.

Findings

Clear anticrossing indicates coupling between graphene plasmons and the Higgs mode.

Higgs mode observable through the Purcell effect with quantum emitters.

Combining superconductor, graphene, and emitters offers new experimental control.

Abstract

We show that the Higgs mode of a superconductor, which is usually challenging to observe by far-field optics, can be made clearly visible using near-field optics by harnessing ultraconfined graphene plasmons. As near-field sources we investigate two examples: graphene plasmons and quantum emitters. In both cases the coupling to the Higgs mode is clearly visible. In the case of the graphene plasmons, the coupling is signaled by a clear anticrossing stemming from the interaction of graphene plasmons with the Higgs mode of the superconductor. In the case of the quantum emitters, the Higgs mode is observable through the Purcell effect. When combining the superconductor, graphene, and the quantum emitters, a number of experimental knobs become available for unveiling and studying the electrodynamics of superconductors.