Entanglement Spectrum, Critical Exponents, and Order Parameters in Quantum Spin Chains

TitleEntanglement Spectrum, Critical Exponents, and Order Parameters in Quantum Spin Chains
Publication TypeJournal Article
Year of Publication2012
AuthorsDe Chiara, G, Lepori, L, Lewenstein, M, Sanpera, A
JournalPhysical Review Letters
Volume109
Date Published12/2012
ISSN1079-7114
Abstract

We investigate the entanglement spectrum near criticality in finite quantum spin chains. Using finite size scaling we show that when approaching a quantum phase transition, the Schmidt gap, i.e., the difference between the two largest eigenvalues of the reduced density matrix λ1, λ2, signals the critical point and scales with universal critical exponents related to the relevant operators of the corresponding perturbed conformal field theory describing the critical point. Such scaling behavior allows us to identify explicitly the Schmidt gap as a local order parameter.

DOI10.1103/PhysRevLett.109.237208
Short TitlePhys. Rev. Lett.
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