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arXiv · 2308.04686

Orthogonality catastrophe and quantum speed limit for dynamical quantum phase transition

Zheng-Rong Zhu·Bin Shao·Jian Zou·Lian-Ao Wu
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Abstract

We investigate the orthogonality catastrophe and quantum speed limit in the Creutz model for dynamical quantum phase transitions. We demonstrate that exact zeros of the Loschmidt echo can exist in finite-size systems for specific discrete values. We highlight the role of the zero-energy mode when analyzing quench dynamics near the critical point. We also examine the behavior of the time for the first exact zeros of the Loschmidt echo and the corresponding quantum speed limit time as the system size increases. While the bound is not tight, it can be attributed to the scaling properties of the band gap and energy variance with respect to system size. As such, we establish a relation between the orthogonality catastrophe and quantum speed limit by referencing the full form of the Loschmidt echo. Significantly, we find the possibility of using the quantum speed limit to detect the critical point of a static quantum phase transition, along with a decrease in the amplitude of noise induced quantum speed limit.

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Zheng-Rong Zhu, Bin Shao, Jian Zou, Lian-Ao Wu. 2023-08-09. Orthogonality catastrophe and quantum speed limit for dynamical quantum phase transition. https://arxiv.org/abs/2308.04686

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