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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-1473
DTSTART:20090514T150000Z
DURATION:PT1H0M0S
DTSTAMP:20260422T164448Z
LAST-MODIFIED:20090505T133124Z
LOCATION:5310 Chamberlin
SUMMARY:Fermionic spinons in two and three dimensions\, R. G. Herb Con
 densed Matter Seminar\, Zhihao Hao\, Johns Hopkins University
DESCRIPTION:The low energy elementary excitations of the Heisenberg mo
 del are magnons\, bosons with integer spin if the system is bipartite 
 and has long range order in the ground state. It has been long conject
 ured that spinons\, fermions with spin one half\, are the effective de
 grees of freedom for spin 1/2 frustrated antiferromagnets. While exist
 ence of spinons is well established in one dimension\, they remain elu
 sive in higher dimensional systems. In this talk we are going to demon
 strate there are fermionic spinons in kagome lattice and hyper-kagome 
 lattice. The spinons are topological excitations and couples strongly 
 to a compact U(1) gauge field. They can also be electrically charged t
 hrough either magnetostriction or higher order perturbation effects. T
 he spinons interact with each other through an exchange mediated attra
 ction and form tightly bound bosonic pairs. The lowest energy triplet 
 excitation of the ground state breaks one such pair into two free spin
 ons at the energy cost of 0.06J\, which is the mechanism responsible f
 or the spin gap of the kagome and hyperkagome lattice.
URL:https://www.physics.wisc.edu/events/?id=1473
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