Modulation of quantum geometry and its coupling to pseudo-electric field by dynamic strain

TL;DR

This paper demonstrates real-time modulation of quantum geometric properties, specifically Berry curvature and the pseudo-electric field, in 2D materials using dynamic strain, enabling new control methods for electronic responses.

Contribution

It introduces a novel method to dynamically modulate quantum geometry and generate pseudo-electric fields in 2D heterostructures through time-dependent strain.

Findings

Measured Hall signals modulated at strain and electric field frequencies

Provided direct evidence of strain-induced pseudo-electric field

Showed control of quantum geometry beyond static perturbations

Abstract

Two-dimensional materials are a fertile ground for exploring quantum geometric phenomena, with Berry curvature and its first moment, the Berry curvature dipole, playing a central role in their electronic response. These geometric properties influence electronic transport and result in the anomalous and nonlinear Hall effects, and are typically controlled using static electric fields or strain. However, the possibility of modulating quantum geometric quantities in real-time remains unexplored. Here, we demonstrate the dynamic modulation of Berry curvature and its moments, as well as the generation of a pseudo-electric field using time-dependent strain. By placing heterostructures on a membrane, we introduce oscillatory strain together with an in-plane AC electric field and measure Hall signals that are modulated at linear combinations of the frequencies of strain and electric field. Our measurements reveal modulation of Berry curvature and its first moment. Notably, we provide direct experimental evidence of pseudo-electric field that results in an unusual dynamic strain-induced Hall response. This approach opens up a new pathway for controlling quantum geometry on demand, moving beyond conventional static perturbations. The pseudo-electric field provides a framework for external electric field-free anomalous Hall response and opens new avenues for probing the topological properties.