Microwave response of a chiral Majorana interferometer

TL;DR

This paper proposes using microwave impedance measurements to directly observe the interference and dynamics of chiral Majorana modes in a topological superconducting interferometer, providing a new experimental approach.

Contribution

It introduces a novel method to probe chiral Majorana fermions via microwave response in a floating superconducting island setup.

Findings

Microwave impedance reveals interference of Majorana modes.

Charging dynamics are controlled by time-delayed Majorana interference.

Proposes microwave measurement as a direct probe of 1D chiral Majorana physics.

Abstract

We consider an interferometer based on artificially induced topological superconductivity and chiral 1D Majorana fermions. The (non-topological) superconducting island inducing the superconducting correlations in the topological substrate is assumed to be floating. This allows probing the physics of interfering Majorana modes via microwave response, i.e., the frequency dependent impedance between the island and the earth. Namely, charging and discharging of the island is controlled by the time-delayed interference of chiral Majorana excitations in both normal and Andreev channels. We argue that microwave measurements provide a direct way to observe the physics of 1D chiral Majorana modes.