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arXiv · 2504.10447

Quantum geometry from the Moyal product: quantum kinetic equation and non-linear response

Takamori Park·Xiaoyang Huang·Lucile Savary·Leon Balents
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Abstract

We systematically derive the dissipationless quantum kinetic equation for a multi-band free fermionic system with U(1) symmetry. Using the Moyal product formalism, we fully band-diagonalize the dynamics. Expanding to the second order in gradients, which is beyond the semiclassical limit, we give a complete analysis of the band-resolved thermodynamics and transport properties, especially those arising from the quantum geometric tensor. We apply our framework to a Bloch band theory under electric fields near equilibrium and find the linear and nonlinear transport coefficients. We also obtain the dynamical density-density response functions in the metallic case, including quantum metric corrections. Our results and approach can be applied very generally to multi-band problems even in situations with spatially varying Hamiltonians and distributions.

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Takamori Park, Xiaoyang Huang, Lucile Savary, Leon Balents. 2025-04-14. Quantum geometry from the Moyal product: quantum kinetic equation and non-linear response. https://arxiv.org/abs/2504.10447

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