Charge density wave modulated third-order nonlinear Hall effect in 1$T$-VSe$_2$ nanosheets

TL;DR

This study demonstrates a pronounced third-order nonlinear Hall effect in 1T-VSe2 nanosheets, significantly enhanced below the charge density wave transition, revealing the influence of symmetry breaking on nonlinear quantum transport.

Contribution

It uncovers the role of charge density wave-induced symmetry breaking in modulating the third-order nonlinear Hall effect in VSe2 nanosheets, with detailed analysis of intrinsic and extrinsic contributions.

Findings

Third-order nonlinear Hall effect observed up to room temperature.

Enhanced effect below the charge density wave transition temperature.

Intrinsic Berry connection polarizability contribution increases in the CDW phase.

Abstract

We report the observation of a pronounced third-order nonlinear Hall effect (NLHE) in 1$T$-phase VSe$_2$ nanosheets, synthesized using chemical vapor deposition (CVD). The nanosheets exhibit a charge density wave (CDW) transition at $\sim$77 K. Detailed angle-resolved and temperature-dependent measurements reveal a strong cubic relationship between the third-harmonic Hall voltage $V_{3\omega}^\perp$ and the bias current $I_\omega$, persisting up to room temperature. Notably, the third-order NLHE demonstrates a twofold angular dependence and significant enhancement below the CDW transition temperature, indicative of threefold symmetry breaking in the CDW phase. Scaling analysis suggests that the intrinsic contribution from the Berry connection polarizability tensor is substantially increased in the CDW phase, while extrinsic effects dominate at higher temperatures. Our findings highlight the critical role of CDW-induced symmetry breaking in modulating quantum geometric properties and nonlinear transport phenomena in VSe$_2$, paving the way for future explorations in low-dimensional quantum materials.