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arXiv · 2601.19152

Evolution of quantum geometric tensor of 1D periodic systems after a quench

Jia-Chen Tang·Xu-Yang Hou·Yu-Huan Huang·Hao Guo. Chih-Chun Chien
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Abstract

We investigate the post-quench dynamics of the quantum geometric tensor (QGT) of 1D periodic systems with a suddenly changed Hamiltonian. The diagonal component with respect to the crystal momentum gives a metric corresponding to the variance of the time-evolved position, and its coefficient of the quadratic term in time is the group-velocity variance, signaling ballistic wavepacket dispersion. The other diagonal QGT component with respect to time reveals the energy variance. The off-diagonal QGT component features a real part as a covariance and an imaginary part representing a quench-induced curvature. Using the Su-Schrieffer-Heeger (SSH) model as an example, our numerical results of different quenches confirm that the post-quench QGT is governed by physical quantities and local geometric objects from the initial state and post-quench bands, such as the Berry connection, group velocities, and energy variance. Furthermore, the connections between the QGT and physical observables suggest the QGT as a comprehensive probe for nonequilibrium phenomena.

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Jia-Chen Tang, Xu-Yang Hou, Yu-Huan Huang, Hao Guo. Chih-Chun Chien. 2026-01-27. Evolution of quantum geometric tensor of 1D periodic systems after a quench. https://doi.org/10.1103/zd1j-dlqg

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