BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Topological order from strong correlations in two-dimensional latt
 ice models - Stefanos Kourtis\, IFW Dresden
DTSTART:20140508T131500Z
DTEND:20140508T141500Z
UID:TALK50124@talks.cam.ac.uk
CONTACT:Dr G Moller
DESCRIPTION:The formation of fractional quantum-Hall (FQH) states in latti
 ce systems without externally applied magnetic fields -- dubbed fractional
  Chern insulators (FCI) -- is a recent and promising theoretical proposal 
 that has the potential to render the FQH effect experimentally more access
 ible. The paradigmatic FCIs are found when interacting electrons with froz
 en spin degree of freedom populate relatively flat topological bands\, wit
 h the interaction strength being smaller than the gap to other bands. In t
 his talk\, I will show that this limit is adiabatically connected to the o
 pposite one\, in which the interaction strength goes to infinity\, thus ex
 ceeding the gap to other bands. Electrons then become extended hard-core p
 articles\, the notion of bands becomes meaningless and the connection to L
 andau level physics of the fractional quantum-Hall effect is much less obv
 ious. FCI states are very robust in this hardcore limit\, reaching up to\,
  or possibly beyond\, the non-interacting topological phase transition. St
 rong interactions may also give rise to competition between topological an
 d conventional charge order. After discussing this competition\, I will in
 troduce a class of states in which the FCI topological order is induced by
  the presence of a charge-density wave and will present numerical evidence
  for this coexistence. Finally\, based on these compositely ordered states
 \, I will provide a recipe for topological order out of a topologically tr
 ivial band structure.
LOCATION:TCM Seminar Room\, Cavendish Laboratory
END:VEVENT
END:VCALENDAR