title: Bulk Topological Proximity Effect.
abstract: Existing proximity effects stem from systems with a local order parameter, such as a local magnetic moment or a local superconducting pairing amplitude. Here, we demonstrate that despite lacking a local order parameter, topological phases also may give rise to a proximity effect of a distinctively inverted nature. We focus on a general construction in which a topological phase is extensively coupled to a second system, and we argue that, in many cases, the inverse topological order will be induced on the second system. To support our arguments, we rigorously establish this "bulk topological proximity effect" for all gapped free-fermion topological phases and representative integrable models of interacting topological phases. We present a terrace construction which illustrates the phenomenological consequences of this proximity effect. Finally, we discuss generalizations beyond our framework, including how intrinsic topological order may also exhibit this effect.
authors.affiliation: Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106, USA.
authors.forename: Timothy H
authors.initials: TH
authors.lastname: Hsieh
authors.affiliation: Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106, USA.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ishizuka
authors.affiliation: Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106, USA.
authors.forename: Leon
authors.initials: L
authors.lastname: Balents
authors.affiliation: Department of Physics, Institute for Condensed Matter Theory, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA.
authors.forename: Taylor L
authors.initials: TL
authors.lastname: Hughes