Regensburg 2010 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 8: CE: (General) Theory
TT 8.2: Vortrag
Montag, 22. März 2010, 14:15–14:30, H21
A model of charge fractionalization on the kagome lattice — •Aroon O’Brien1, Frank Pollmann2, Nic Shannon3, and Peter Fulde1,4 — 1Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, 01187 Dresden, Germany — 2University of California, Berkeley, CA94720, USA — 3H.H. Wills Physics Laboratory, University of Bristol, Tyndall Ave, BS8-1TL, UK — 4Asia Pacific Center for Theoretical Physics, Pohang, Korea
Geometrically frustrated models exhibit many fascinating physical properties, one of which is the possible existence of fractionally charged excitations [1]. Such excitations may arise here as a consequence of the frustrated electronic interactions [2]. We have investigated a model of spinless fermions on the 2D kagome lattice, for which fractionally charged excitations occur in the limit of strong correlations at 1/3 filling. Here we present results for the dynamical properties of the fractional charges, as revealed by numerically calculated spectral functions. Particular focus is given to the signatures of fractional confined collective excitations observed in these spectra [3]. Recently a scheme for a quantum simulation of this model using cold atoms was proposed; we relate this to numerically calculated quantities that we argue may be measurable in optical lattice experiments [4].
[1] P. Fulde, K. Penc, N. Shannon, Ann. Phys., 11, 892 (2002).
[2] F. Pollmann and P. Fulde, Europhys. Lett., 75, 133 (2006).
[3] A. O’Brien, F. Pollmann and P. Fulde, to be submitted.
[4] J. Ruostekoski, Phys. Rev. Lett., 103, 080406 (2009); J. Ruostekoski and N. Shannon, in preparation.