Regensburg 2016 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 73: Low-Dimensional Systems: Topological Order

TT 73.5: Vortrag

Donnerstag, 10. März 2016, 16:00–16:15, H19

Topological edge states in a one-dimensional ladder system — •Kai-Simon Guther, Nicolai Lang, and Hans Peter Büchler — Institut für Theoretische Physik III, Universität Stuttgart

We consider an interacting, particle number conserving model of fermions in a two-wire system. An exact solution for the ground state is possible for a special choice of parameters, and the occurence of topological edge states with non-Abelian statistics has been proven previously analytically [1].

We analyze the stability of the edge states and the corresponding ground state degeneracy away from the exactly solvable point. Therefore, we empoly both a perturbative approach using bosonization as well as the numerical method of density matrix renormalization group. We demonstrate the stability of the edge state under certain perturbations while other perturbations lead to the occurence of a phase separation. We derive the phase diagram in which the exactly solvable point is located at a phase boundary similar to that appearing in a model considered in [2].

[1] N. Lang and H. P. Büchler, PRB 92, 041118 (2015)

[2] F. Iemini et al., PRL 115, 156402 (2015)