Quantum metric and wavepackets at exceptional points in non-Hermitian systems

• URL: http://arxiv.org/abs/2009.06987v1
• Date: Tue, 15 Sep 2020 11:15:09 GMT
• Title: Quantum metric and wavepackets at exceptional points in non-Hermitian systems
• Authors: D. D. Solnyshkov, C. Leblanc, L. Bessonart, A. Nalitov, J. Ren, Q. Liao, F. Li, G. Malpuech
• Abstract summary: We show that the quantum metric becomes a crucial quantity near exceptional points in non-Hermitian systems. 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.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• 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.

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