CMTC Seminar

Calendar
Department of Physics Calendar
Date
Wed, Jun 20, 2018 11:00 am - 12:15 pm
Location
CMTC Conference Room (Toll 2205)

Description

Speaker: Christopher Mudry (Paul Scherrer Institute)

Tite: A model of chiral spin liquids with tunable chiral edge states

Abstract: We present a two-dimensional lattice model for quantum spin-1/2
for which the low-energy limit is governed by four flavors of strongly
interacting Majorana fermions. We study this low-energy effective theory
using two alternative approaches. The first consists of a mean-field
approximation. The second consists of a Random Phase approximation (RPA)
for the single-particle Green's functions of the Majorana fermions built
from their exact forms in a certain one-dimensional limit. The resulting
phase diagram consists of two competing chiral phases, one with Abelian
and the other with non-Abelian topological order, separated by a
continuous phase transition. Remarkably, the Majorana fermions propagate
in the two-dimensional bulk, as in the Kitaev model for a spin liquid on
the honeycomb lattice. We identify the vison fields, which are mobile
(they are static in the Kitaev model) domain walls propagating along only
one of the two space directions.