Energy-Resolved Quantum Geometry from St\v{r}eda Response: Driven-Dissipative Bosonic Lattices and Disordered Systems

TL;DR

This paper introduces a method using driven-dissipative bosonic lattices to measure energy-resolved quantum geometry and topological features, including disorder effects, via the Středa response.

Contribution

It demonstrates how controlled pumping and loss in bosonic lattices enable reconstruction of energy-resolved Středa responses, revealing quantum geometry and topological disorder effects.

Findings

Reconstruction of energy-resolved Středa response in bosonic lattices.

Identification of quantum-geometric structures in topological Anderson insulators.

Probing of spectral flow and disorder effects through the Středa marker.

Abstract

The St\v{r}eda formula links the Hall conductivity of an insulator to the magnetic-field response of its particle density, providing a local and universal probe of the topological Chern number. Beyond this quantized response, an energy-resolved St\v{r}eda marker can be defined from the magnetic response of the density of states, revealing detailed features of the quantum geometry of Bloch bands. We show that driven-dissipative bosonic lattices provide direct access to both the integrated and energy-resolved St\v{r}eda responses. Our scheme uses controlled pumping with uniform strength and random phases across the lattice, together with uniform loss, to yield a Lorentzian filter of eigenmode occupations. For generic dispersive bands, this enables reconstruction of a coarse-grained energy-resolved St\v{r}eda response, establishing these platforms as versatile probes of anomalous spectral flow and energy-resolved quantum geometry. As a striking application, we show that this marker elucidates the fate of topological bands under strong disorder, capturing the quantum-geometric structure underlying topological Anderson insulators.