Microwave Spectroscopy Reveals the Quantum Geometric Tensor of Topological Josephson Matter

TL;DR

This paper proposes a method to experimentally access the quantum geometric tensor of Andreev states in topological Josephson junctions using microwaves, revealing their topological quantum properties.

Contribution

It introduces a technique to measure the quantum geometric tensor in topological Josephson matter via microwave spectroscopy, linking absorption rates to topological invariants.

Findings

Quantum geometric tensor can be extracted from microwave absorption data.

Oscillator strength reveals topological properties of Andreev states.

Method provides a new way to probe topological quantum states experimentally.

Abstract

Quantization effects due to topological invariants such as Chern numbers have become very relevant in many systems, yet key quantities such as the quantum geometric tensor providing local information about quantum states remain experimentally difficult to access. Recently, it has been shown that multiterminal Josephson junctions constitute an ideal platform to synthesize topological systems in a controlled manner. We theoretically study properties of Andreev states in topological Josephson matter and demonstrate that the quantum geometric tensor of Andreev states can be extracted by synthetically polarized microwaves. The oscillator strength of the absorption rates provides direct evidence of topological quantum properties of the Andreev states.