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Bibliographic Details
Main Authors: Bhowmick, Dibyanandan, Agarwal, Amit
Format: Preprint
Published: 2025
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Online Access:https://arxiv.org/abs/2509.20647
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author Bhowmick, Dibyanandan
Agarwal, Amit
author_facet Bhowmick, Dibyanandan
Agarwal, Amit
contents Electrical current fluctuations provide a powerful and unconventional probe of band geometry in quantum materials. In particular, intrinsic noise components that are independent of the relaxation time reveal universal band-geometric properties of Bloch electrons. Here, we identify a distinct intrinsic contribution to current noise at second order in the electric field, which is governed by the quantum metric. This effect arises from field-induced modifications to Bloch wavefunctions and band energies, and it dominates in PT-symmetric antiferromagnets where Berry curvature based contributions are forbidden by symmetry. Applying our theory to CuMnAs, we demonstrate that thermal noise provides a direct signature of quantum metric in PT-symmetric antiferromagnets.
format Preprint
id arxiv_https___arxiv_org_abs_2509_20647
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Quantum metric induced nonlinear thermal noise in PT-symmetric antiferromagnets
Bhowmick, Dibyanandan
Agarwal, Amit
Mesoscale and Nanoscale Physics
Electrical current fluctuations provide a powerful and unconventional probe of band geometry in quantum materials. In particular, intrinsic noise components that are independent of the relaxation time reveal universal band-geometric properties of Bloch electrons. Here, we identify a distinct intrinsic contribution to current noise at second order in the electric field, which is governed by the quantum metric. This effect arises from field-induced modifications to Bloch wavefunctions and band energies, and it dominates in PT-symmetric antiferromagnets where Berry curvature based contributions are forbidden by symmetry. Applying our theory to CuMnAs, we demonstrate that thermal noise provides a direct signature of quantum metric in PT-symmetric antiferromagnets.
title Quantum metric induced nonlinear thermal noise in PT-symmetric antiferromagnets
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2509.20647