Quantum-geometric shift of quasiequilibrium: Origin of nonreciprocal current driven by quantum-metric dipole

@misc{kitamura2026quantumgeometric,
  title = {{Quantum-geometric shift of quasiequilibrium: Origin of nonreciprocal current driven by quantum-metric dipole}},
  author = {Sota Kitamura and Takahiro Anan and Takahiro Morimoto},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2607.02100},
  eprint = {2607.02100},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2607.02100},
}

TY  - UNPB
TI  - Quantum-geometric shift of quasiequilibrium: Origin of nonreciprocal current driven by quantum-metric dipole
AU  - Sota Kitamura
AU  - Takahiro Anan
AU  - Takahiro Morimoto
PY  - 2026
DA  - 2026/09/25
PB  - arXiv
DO  - 10.48550/arxiv.2607.02100
UR  - https://arxiv.org/abs/2607.02100
AB  - We study nonlinear DC electric transport of quantum-metric origin by combining adiabatic perturbation theory with the nonequilibrium Green function approach. The adiabatic ansatz provides a basis for directly treating a DC electric field in the velocity gauge, rather than introducing it as the zero-frequency limit of an AC field. The resulting adiabatic-basis Hamiltonian takes the same form as in the length gauge, enabling a systematic comparison across different formulations. Applying this fully quantum formulation, we find a longitudinal nonreciprocal current governed by the quantum-metric dipole. The essential ingredient is a quantum correction to the distribution function that is absent in semiclassical treatments. We trace this correction to the finite spread of an electron wave packet during relaxation under a bias field, thereby identifying shifted quasiequilibrium as the physical origin of quantum-metric nonreciprocal transport.
ER  -