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arXiv · 1311.4437

Complexity and instability of quantum motion near a quantum phase transition

Pinquan Qin·Wen-ge Wang·Giuliano Benenti·Giulio Casati
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Abstract

We show that the number of harmonics of the Wigner function, recently proposed as a measure of quantum complexity, can be also used to characterize quantum phase transitions. The non-analytic behavior of this quantity in the neighborhood of a quantum phase transition is illustrated by means of the Dicke model and is compared to two well-known measures of the (in)stability of quantum motion, the quantum Loschmidt echo and the fidelity.

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Pinquan Qin, Wen-ge Wang, Giuliano Benenti, Giulio Casati. 2014-03-31. Complexity and instability of quantum motion near a quantum phase transition. https://doi.org/10.1103/physreve.89.032120

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