Topological insulators and their implications for electronic
order
Joel Moore, U C Berkeley
Much of condensed matter physics is concerned with understanding how
different kinds of order emerge from interactions between a large
number
of simple constituents. In ordered phases such as crystals, magnets,
and
superfluids, the order is understood through symmetry
breaking. A major
discovery of the 1980s was that electrons confined to two dimensions
and
in a strong magnetic field exhibit a completely different,
"topological" order
in the quantum Hall regime. Topological order was recently
discovered in
some three-dimensional materials, dubbed topological insulators, in
zero
magnetic field. Spin-orbit coupling, an intrinsic property of all
solids, drives
the formation of the topological state. The first part of the
talk will explain how
topological insulators were predicted and discovered by building on
the
quantum Hall effect. The second part will cover more recent
work on
connections between topological insulators, magnetoelectric effects
("axion
electrodynamics"), and strong correlation effects.