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

Pichler, Hannes and Bonnes, Lars and Daley, Andrew J and Läuchli, Andreas M and Zoller, Peter (2013) Thermal versus entanglement entropy : a measurement protocol for fermionic atoms with a quantum gas microscope. New Journal of Physics, 15. 063003. ISSN 1367-2630 (https://doi.org/10.1088/1367-2630/15/6/063003)

[thumbnail of Pichler-etal-NJP-2013-Thermal-versus-entanglement-entropy]
Preview
Text. Filename: Pichler_etal_NJP_2013_Thermal_versus_entanglement_entropy.pdf
Final Published Version
License: Creative Commons Attribution 3.0 logo

Download (682kB)| Preview

Abstract

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.