1202.4460 (Ara Go et al.)

Correlated topological phases in 3D complex oxides via Green's functions    [PDF]

Ara Go, William Witczak-Krempa, Gun Sang Jeon, Kwon Park, Yong Baek Kim

We examine the effects of correlations on 3D topological insulators (TIs) as
well as topological Weyl semimetals by using cellular dynamical mean-field
theory (CDMFT). A model relevant to the pyrochlore iridates, a family of
complex oxides that might harbour such phases, is used. We characterize the
evolution of the topologically protected surface states and their disappearance
for sufficiently strong interactions. We verify the bulk-boundary
correspondence for correlated TIs by computing the quantized magneto-electric
response coefficient using the interacting Green's function. This invariant
also identifies a correlated axion insulator between a TI and Weyl semimetal, a
feature absent in a simple mean-field treatment. We describe consequences for
experiments and for the search for correlated materials with symmetry-protected
topological order.

View original: http://arxiv.org/abs/1202.4460