2009/02/28 by Babak Seradjeh, B. Seradjeh, Joel E. Moore +3 · 5 citations
Materials Science · Physics and Astronomy · #Graphene research and applications #Quantum many-body systems #Topological Materials and Phenomena #cond-mat.mes-hall #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.103.066402
published as Phys. Rev. Lett. 103, 066402 (2009). · 4 pages, 1 figure, version to appear in PRL (minor stylistic changes). For related work and info visit http://www.physics.ubc.ca/~franz/
arxiv created 2009/07/16 · openalex publication_date 2009/08/07 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
An odd number of gapless Dirac fermions is guaranteed to exist at a surface of a strong topological insulator. We show that in a thin-film geometry and under external bias, electron-hole pairs that reside in these surface states can condense to form a novel exotic quantum state which we propose to call "topological exciton condensate" (TEC). This TEC is similar in general terms to the exciton condensate recently argued to exist in a biased graphene bilayer, but with different topological properties. It exhibits a host of unusual properties including a stable zero mode and a fractional charge +/-e/2 carried by a singly quantized vortex in the TEC order parameter.