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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-2023
DTSTART:20110331T150000Z
DURATION:PT1H0M0S
DTSTAMP:20260414T165244Z
LAST-MODIFIED:20110321T173927Z
LOCATION:5310 Chamberlin
SUMMARY:Quantum Phases of the Cairo Pentagonal Lattice\, R. G. Herb Co
 ndensed Matter Seminar\, Ioannis Rousochatzakis\, Max-Planck Insitute 
 for the Physics of Complex Systems\, Dresden
DESCRIPTION:We present an analytical and numerical study of the spin S
 =1/2 antiferromagnetic Heisenberg model on the Cairo pentagonal lattic
 e. This is the dual of the Shastry-Sutherland lattice and has been dis
 cussed as a possible new candidate for having a spin liquid ground sta
 te [1]. More recently a S=5/2 version of this model has been realized 
 in the Bi2Fe4O9 system [2]. Here we use a model with two different typ
 es of exchange couplings and investigate the nature of the ground stat
 e as a function of their ratio. This strategy allows us to understand 
 the nature of a number of phases and derive effective models for their
  description with and without a magnetic field. Of particular interest
  is a surprising interplay between a collinear and a four-sublattice o
 rthogonal phase due to an underlying order-by-disorder mechanism. Furt
 hermore we address the issue of possible nonmagnetic ground states suc
 h as singlet and spin nematic phases.<br>
\n<br>
\nReferences:<br>
\n[
 1] K. S. Raman\, R. Moessner\, and S. L. Sondhi\, PRB 72\, 064413 (200
 5)<br>
\n[2] E. Ressouche\, V. Simonet\, B. Canals\, M. Gospodinov\, a
 nd V. Skumryev\, PRL 103\, 267204 (2009)
URL:https://www.physics.wisc.edu/events/?id=2023
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