Journal of High Energy Physics (Oct 2021)

Complexity from the reduced density matrix: a new diagnostic for chaos

  • Arpan Bhattacharyya,
  • S. Shajidul Haque,
  • Eugene H. Kim

DOI
https://doi.org/10.1007/JHEP10(2021)028
Journal volume & issue
Vol. 2021, no. 10
pp. 1 – 23

Abstract

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Abstract We investigate circuit complexity to characterize chaos in multiparticle quantum systems. In the process, we take a stride to analyze open quantum systems by using complexity. We propose a new diagnostic of quantum chaos from complexity based on the reduced density matrix by exploring different types of quantum circuits. Through explicit calculations on a toy model of two coupled harmonic oscillators, where one or both of the oscillators are inverted, we demonstrate that the evolution of complexity is a possible diagnostic of chaos.

Keywords