Ground-state quantum geometry in superconductor-quantum dot chains

TL;DR

This paper proposes a feasible experimental setup using multiterminal quantum dots and microwave spectroscopy to measure quantum geometry and topology, specifically the many-body Chern number, in superconductor-quantum dot chains.

Contribution

It introduces a new multiterminal quantum dot setup and extends microwave spectroscopy techniques to access quantum geometric tensor elements in the ground state.

Findings

Proposed a setup for measuring quantum geometry in quantum dot chains.

Extended microwave spectroscopy to multiband systems.

Showed that oscillator strengths reveal quantum geometric tensor elements.

Abstract

Multiterminal Josephson junctions constitute engineered topological systems in arbitrary synthetic dimensions defined by the superconducting phases. Microwave spectroscopy enables the measurement of the quantum geometric tensor, a fundamental quantity describing both the quantum geometry and the topology of the emergent Andreev bound states in a unified manner. In this work we propose an experimentally feasible multiterminal setup of $N$ quantum dots connected to $N+1$ superconducting leads to study nontrivial topology in terms of the many-body Chern number of the ground state. Moreover, we generalize the microwave spectroscopy scheme to the multiband case and show that the elements of the quantum geometric tensor of the noninteracting ground state can be experimentally accessed from the measurable oscillator strengths at low temperature.