Topological insulators with arbitrarily tunable entanglement

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • J. C. Budich - , Österreichische Akademie der Wissenschaften, Universität Innsbruck, Stockholm University (Autor:in)
  • J. Eisert - , Freie Universität (FU) Berlin (Autor:in)
  • E. J. Bergholtz - , Freie Universität (FU) Berlin (Autor:in)

Abstract

We elucidate how Chern and topological insulators fulfill an area law for the entanglement entropy. By explicit construction of a family of lattice Hamiltonians, we are able to demonstrate that the area law contribution can be tuned to an arbitrarily small value but is topologically protected from vanishing exactly. We prove this by introducing novel methods to bound entanglement entropies from correlations using perturbation bounds, drawing intuition from ideas of quantum information theory. This rigorous approach is complemented by an intuitive understanding in terms of entanglement edge states. These insights have a number of important consequences: The area law has no universal component, no matter how small, and the entanglement scaling cannot be used as a faithful diagnostic of topological insulators. This holds for all Renyi entropies which uniquely determine the entanglement spectrum, which is hence also nonuniversal. The existence of arbitrarily weakly entangled topological insulators furthermore opens up possibilities of devising correlated topological phases in which the entanglement entropy is small and which are thereby numerically tractable, specifically in tensor network approaches.

Details

OriginalspracheEnglisch
Aufsatznummer195120
FachzeitschriftPhysical Review B - Condensed Matter and Materials Physics
Jahrgang89
Ausgabenummer19
PublikationsstatusVeröffentlicht - 15 Mai 2014
Peer-Review-StatusJa
Extern publiziertJa