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arXiv · 2605.16367

Nonlinear Ohmic electromagnetic response

Anwei Zhang·Zheng Cai·C. M. Wang
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Abstract

We systematically investigate nonlinear Ohmic responses in second-harmonic generation and bilinear magnetoelectric effects within the Matsubara Green's function formalism. The optical nonlinear Ohmic conductivity is shown to consist of a nonlinear Drude-like part and an intrinsic term determined by the fully symmetrized normalized quantum metric dipole. Notably, we predict a previously unrecognized intrinsic Ohmic conductivity arising from band geometry in the bilinear magnetoelectric response, which exhibits transverse behavior similar to its optical counterpart. Using a two-dimensional Dirac model, we demonstrate that this geometrically induced nonlinear Ohmic response is observable in materials with high Fermi velocity and narrow band gaps. Our work provides a systematic quantum field-theoretic framework for describing nonlinear Ohmic transport in condensed matter systems.

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Anwei Zhang, Zheng Cai, C. M. Wang. 2026-05-10. Nonlinear Ohmic electromagnetic response. https://arxiv.org/abs/2605.16367

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