Quantum metric and wavepackets at exceptional points in non-Hermitian systems
Mesoscale and Nanoscale Physics
2021-03-17 v1 Optics
Quantum Physics
Abstract
The usual concepts of topological physics, such as the Berry curvature, cannot be applied directly to non-Hermitian systems. We show that another object, the quantum metric, which often plays a secondary role in Hermitian systems, becomes a crucial quantity near exceptional points in non-Hermitian systems, where it diverges in a way that fully controls the description of wavepacket trajectories. The quantum metric behaviour is responsible for a constant acceleration with a fixed direction, and for a non-vanishing constant velocity with a controllable direction. Both contributions are independent of the wavepacket size.
Cite
@article{arxiv.2009.06987,
title = {Quantum metric and wavepackets at exceptional points in non-Hermitian systems},
author = {D. D. Solnyshkov and C. Leblanc and L. Bessonart and A. Nalitov and J. Ren and Q. Liao and F. Li and G. Malpuech},
journal= {arXiv preprint arXiv:2009.06987},
year = {2021}
}