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SUMMARY:Bulk-boundary correspondence of topological insulators - Prof. Vic
 tor Gurarie\, University of Colorado at Boulder
DTSTART:20110512T131500Z
DTEND:20110512T141500Z
UID:TALK30178@talks.cam.ac.uk
CONTACT:Dr G Moller
DESCRIPTION:Topological insulators are noninteracting gapful fermionic sys
 tems which have gapless boundary excitations. They are characterized by to
 pological invariants. The topological invariants can be written in many di
 fferent ways\, including in terms of the Green’s functions. We show that
  the existence of the boundary states directly follows\, and can be derive
 d by simple manipulations\, from the existence of the bulk topological inv
 ariant written in terms of the Green’s functions\, for all types of topo
 logical insulators in all spacial dimensions. At the same time\, the same 
 procedure explains why topological insulators\, once the interactions are 
 turned on\, can lose their boundary states.
LOCATION:TCM Seminar Room\, Cavendish Laboratory
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