Entanglement at a two-dimensional quantum critical point: a T = 0 projector quantum Monte Carlo study

Although the leading-order scaling of entanglement entropy is non-universal at a quantum critical point (QCP), sub-leading scaling can contain universal behaviour. Such universal quantities are commonly studied in non-interacting field theories, however it typically requires numerical calculation to...

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Main Authors: Stephen Inglis, Roger G Melko
Format: Article
Language:English
Published: IOP Publishing 2013-01-01
Series:New Journal of Physics
Online Access:https://doi.org/10.1088/1367-2630/15/7/073048
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author Stephen Inglis
Roger G Melko
author_facet Stephen Inglis
Roger G Melko
author_sort Stephen Inglis
collection DOAJ
description Although the leading-order scaling of entanglement entropy is non-universal at a quantum critical point (QCP), sub-leading scaling can contain universal behaviour. Such universal quantities are commonly studied in non-interacting field theories, however it typically requires numerical calculation to access them in interacting theories. In this paper, we use large-scale T  = 0 quantum Monte Carlo simulations to examine in detail the second Rényi entropy of entangled regions at the QCP in the transverse-field Ising model in 2 + 1 space–time dimensions—a fixed point for which there is no exact result for the scaling of entanglement entropy. We calculate a universal coefficient of a vertex-induced logarithmic scaling for a polygonal entangled subregion, and compare the result to interacting and non-interacting theories. We also examine the shape-dependence of the Rényi entropy for finite-size toroidal lattices divided into two entangled cylinders by smooth boundaries. Remarkably, we find that the dependence on cylinder length follows a shape-dependent function calculated previously by Stephan et al  (2013 New J. Phys. 15 015004) at the QCP corresponding to the 2 + 1 dimensional quantum Lifshitz free scalar field theory. The quality of the fit of our data to this scaling function, as well as the apparent cutoff-independent coefficient that results, presents tantalizing evidence that this function may reflect universal behaviour across these and other very disparate QCPs in 2 + 1 dimensional systems.
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spelling doaj.art-8846749b68bb45dcaf1104856eb74e982023-08-08T11:28:16ZengIOP PublishingNew Journal of Physics1367-26302013-01-0115707304810.1088/1367-2630/15/7/073048Entanglement at a two-dimensional quantum critical point: a T = 0 projector quantum Monte Carlo studyStephen Inglis0Roger G Melko1Department of Physics and Astronomy, University of Waterloo , Ontario N2L 3G1, CanadaDepartment of Physics and Astronomy, University of Waterloo , Ontario N2L 3G1, Canada; Perimeter Institute for Theoretical Physics , Waterloo, Ontario N2L 2Y5, CanadaAlthough the leading-order scaling of entanglement entropy is non-universal at a quantum critical point (QCP), sub-leading scaling can contain universal behaviour. Such universal quantities are commonly studied in non-interacting field theories, however it typically requires numerical calculation to access them in interacting theories. In this paper, we use large-scale T  = 0 quantum Monte Carlo simulations to examine in detail the second Rényi entropy of entangled regions at the QCP in the transverse-field Ising model in 2 + 1 space–time dimensions—a fixed point for which there is no exact result for the scaling of entanglement entropy. We calculate a universal coefficient of a vertex-induced logarithmic scaling for a polygonal entangled subregion, and compare the result to interacting and non-interacting theories. We also examine the shape-dependence of the Rényi entropy for finite-size toroidal lattices divided into two entangled cylinders by smooth boundaries. Remarkably, we find that the dependence on cylinder length follows a shape-dependent function calculated previously by Stephan et al  (2013 New J. Phys. 15 015004) at the QCP corresponding to the 2 + 1 dimensional quantum Lifshitz free scalar field theory. The quality of the fit of our data to this scaling function, as well as the apparent cutoff-independent coefficient that results, presents tantalizing evidence that this function may reflect universal behaviour across these and other very disparate QCPs in 2 + 1 dimensional systems.https://doi.org/10.1088/1367-2630/15/7/073048
spellingShingle Stephen Inglis
Roger G Melko
Entanglement at a two-dimensional quantum critical point: a T = 0 projector quantum Monte Carlo study
New Journal of Physics
title Entanglement at a two-dimensional quantum critical point: a T = 0 projector quantum Monte Carlo study
title_full Entanglement at a two-dimensional quantum critical point: a T = 0 projector quantum Monte Carlo study
title_fullStr Entanglement at a two-dimensional quantum critical point: a T = 0 projector quantum Monte Carlo study
title_full_unstemmed Entanglement at a two-dimensional quantum critical point: a T = 0 projector quantum Monte Carlo study
title_short Entanglement at a two-dimensional quantum critical point: a T = 0 projector quantum Monte Carlo study
title_sort entanglement at a two dimensional quantum critical point a t 0 projector quantum monte carlo study
url https://doi.org/10.1088/1367-2630/15/7/073048
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AT rogergmelko entanglementatatwodimensionalquantumcriticalpointat0projectorquantummontecarlostudy