Harnessing hidden quantum metric response in a 2D magnet via nonlocal photovoltaic effect

TL;DR

This paper reveals hidden quantum metric responses in 2D magnetic semiconductors using a nonlocal photovoltaic scheme, enabling new sensing and computing functionalities.

Contribution

It demonstrates the detection of hidden quantum metric responses in centrosymmetric materials via a novel nonlocal photovoltaic approach.

Findings

Hidden quantum metric response can survive in centrosymmetric systems.

Reconfigurable, nonvolatile photodetection enabled by quantum metric response.

Detection of quantum metric effects across magnetic states and ultrathin limits.

Abstract

The quantum geometry of Bloch wavefunctions underpins a wealth of emergent phenomena in quantum materials. Its imaginary part, the Berry curvature, has long been recognized as a key source for hallmark effects such as quantum Hall and topological phenomena, etc. The real part of quantum geometry, the quantum metric, has recently garnered considerable attention due to predictions of a range of unconventional nonlinear and nonequilibrium responses. Such responses usually vanish in centrosymmetric systems, largely restricting relevant studies to non-centrosymmetric materials. Here we challenge this convention by revealing that the vanished quantum metric response can survive in a hidden form. Using a non-local photovoltaic scheme in a layered magnetic semiconductor, we spatially separate mutually compensating photocurrents and thereby detect such hidden quantum metric response. We demonstrate this effect across distinct magnetic states and down to the ultrathin limit. Moreover, we realize reconfigurable, nonvolatile and probabilistic photodetection enabled by the quantum metric response. These results not only fundamentally expand the material landscape for quantum geometric physics, but also open new gateway to harvest the quantum geometric contributions for state-of-the-art nonvolatile reprogrammable sensing and computing applications.