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112nd SPring-8 Seminar

Subtitle/Subject Extended Hubbard model on pyrochlore lattice: ice-rules and fractional charges
Period to Feb 17 , 2004
Host/Organizer JASRI/SPring-8
Format Lecture
Fields Materials Science

Date&Time: 16:00, 17 Feb 2004

Speaker: Dr. Karlo Penc
Affiliation: Research Institute for Solid State Physics, Budapest, Hungary

  The quarter-filled Hubbard model extended with nearest neighbor repulsion on the pyrochlore lattice is an insulator for sufficiently large couplings, with an extensive ground state degeneracy. The model can be mapped to the ice- and the 6-vertex problems.
  The large degeneracy in the ground state manifold can support topological excitations with e/2 charge. Quantitative results are presented for the two-dimensional bosonic version of the problem, the XXZ Heisenberg model, where we discuss the effect of quantum fluctuations and the spinon deconfinement.

Contact Address Junichiro Mizuki (PHS 3902) JASRI/SPring-8

Last modified 2006-04-08 17:01