Thermal versus entanglement entropy: a measurement protocol for fermionic atoms with a quantum gas microscope

Hannes Pichler, Lars Bonnes, Andrew J Daley, Andreas M Läuchli, Peter Zoller

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We show how to measure the order-two Renyi entropy of many-body states of spinful fermionic atoms in an optical lattice in equilibrium and non-equilibrium situations. The proposed scheme relies on the possibility to produce and couple two copies of the state under investigation, and to measure the occupation number in a site- and spin-resolved manner, e.g. with a quantum gas microscope. Such a protocol opens the possibility to measure entanglement and test a number of theoretical predictions, such as area laws and their corrections. As an illustration we discuss the interplay between thermal and entanglement entropy for a one dimensional Fermi-Hubbard model at finite temperature, and its possible measurement in an experiment using the present scheme. 

Original languageEnglish
Article number063003
Number of pages17
JournalNew Journal of Physics
Publication statusPublished - 6 Jun 2013


  • Renyi entropy
  • spinful fermionic atoms
  • optical lattice
  • equilibrium
  • nonequilibrium
  • entanglement
  • Fermi–Hubbard models

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