Ashvin Vishwanath, University of California at Berkeley
February 19

The idea that states of matter are governed by new emergent laws – 'More
is Different' – has been the guiding principle in the theory of solids.
Largely, this was exemplified by symmetry breaking states such as
superfluids and ferromagnets, which are ultimately described by a
classical order parameter, despite being composed of quantum mechanical
particles. However, experimental results over the last several years have
impelled us to look for new forms of emergence that are intrinsically
quantum mechanical. I will briefly discuss topological insulators, a newly
discovered class of solids with strong spin orbit-interactions where
topology forms the basis of a subtle distinction from ordinary insulators.
Subsequently, I will talk about strongly interacting systems like
frustrated magnets that realize even more exotic phases and how quantum
entanglement can serve as a fingerprint of these novel states.

 

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