Online Workshop on Qubits and Black Holes
December 7-9, 2020

Main Menu    Scientific Program

Chris Akers, Massachusetts Institute of Technology
Adam Bouland, University of California, Berkeley
Netta Engelhardt, Massachusetts Institute of Technology
Lampros Lamprou, Massachusetts Institute of Technology

Javier Magan, Instituto Balseiro, Centro Atómico de Bariloche

Title: Entropic Order Parameters for the Phases of QFT
Abstract: We start by describing how generalized symmetries in QFT arise in the violation of elementary properties that appear when we associate algebras to regions in QFT. This observation provides a new perspective/proof of the abelian nature of generalized symmetries. Further, the algebra of order/disorder parameters is fixed and can be deduced without the explicit construction of the non-local operators. In these scenarios, there are two natural algebras associated with regions of specific topologies, suggesting a simple geometrical order parameter defined as a relative entropy. These relative entropies satisfy a “certainty relation” connecting the statistics of the order and disorder parameters. We describe old and new aspects of the phases of QFT’s with generalized symmetries from this perspective. In particular, the certainty relation makes transparent the duality between constant and area law behaviors in symmetry-breaking scenarios, and in CFT’s there are relative entropies exactly computable.

Alex May, University of British Columbia
Thomas Mertens, Ghent University
Geoffrey Penington, University of California, Berkeley

Mukund Rangamani, University of California, Davis
Monika Schleier-Smith, Stanford University
Douglas Stanford, Stanford University

Edward Witten, Institute for Advanced Study