Berlin 2015 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
TT: Fachverband Tiefe Temperaturen
TT 90: Low-Dimensional Systems: Topological Order 1 (jointly with DS, HL, MA, O)
TT 90.3: Talk
Thursday, March 19, 2015, 12:00–12:15, H 3010
Wire deconstructionism of two-dimensional topological phases — •Ronny Thomale1, Titus Neupert2, Claudio Chamon3, and Christopher Mudry4 — 1Institut für Theoretische Physik, Universität Würzburg, Germany — 2Princeton University, USA — 3Boston University, USA — 4PSI Zürich, Switzerland
A scheme is proposed to construct integer and fractional topological quantum states of fermions in two spatial dimensions. We devise models for such states by coupling wires of non-chiral Luttinger liquids of electrons, that are arranged in a periodic array. Which inter-wire couplings are allowed is dictated by symmetry and the compatibility criterion that they can simultaneously acquire a finite expectation value, opening a spectral gap between the ground state(s) and all excited states in the bulk. First, with these criteria at hand, we reproduce the tenfold classification table of integer topological insulators, where their stability against interactions becomes immediately transparent in the Luttinger liquid description. Second, we construct an example of a strongly interacting fermionic topological phase of matter with short-range entanglement that lies outside of the tenfold classification. Third, we expand the table to long-range entangled topological phases with intrinsic topological order and fractional excitations.