Rényi Generalization of the Accessible Entanglement Entropy

• Published in: Physical review letters Vol. 121; no. 15; p. 150501
• Main Authors: Barghathi, Hatem, Herdman, C M, Del Maestro, Adrian
• Format: Journal Article
• Language: English
• Published: United States 12.10.2018
• ISSN: 1079-7114
• DOI: 10.1103/PhysRevLett.121.150501

Operationally accessible entanglement in bipartite systems of indistinguishable particles could be reduced due to restrictions on the allowed local operations as a result of particle number conservation. In order to quantify this effect, Wiseman and Vaccaro [Phys. Rev. Lett. 91, 097902 (2003)PRLTAO0031-900710.1103/PhysRevLett.91.097902] introduced an operational measure of the von Neumann entanglement entropy. Motivated by advances in measuring Rényi entropies in quantum many-body systems subject to conservation laws, we derive a generalization of the operationally accessible entanglement that is both computationally and experimentally measurable. Using the Widom theorem, we investigate its scaling with the size of a spatial subregion for free fermions and find a logarithmically violated area law scaling, similar to the spatial entanglement entropy, with at most a double-log leading-order correction. A modification of the correlation matrix method confirms our findings in systems of up to 10^{5} particles.