Journal of High Energy Physics (Sep 2022)

Target space entanglement in quantum mechanics of fermions at finite temperature

  • Temma Hanyuda,
  • Soichiro Mori,
  • Sotaro Sugishita

DOI
https://doi.org/10.1007/JHEP09(2022)152
Journal volume & issue
Vol. 2022, no. 9
pp. 1 – 42

Abstract

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Abstract We consider the target space entanglement in quantum mechanics of non-interacting fermions at finite temperature. Unlike pure states investigated in [1], the (Rényi) entanglement entropy for thermal states does not follow a simple bound because all states in the infinite-dimensional Hilbert space are involved. We investigate a general formula of the target space Rényi entropy for N fermions at finite temperature, and present numerical results of the entropy in a one-dimensional model. We also argue the large N behaviors with a comparison to the grand canonical ensemble.

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