Strong-coupling expansion for ultracold bosons in an optical lattice at finite temperatures in the presence of superfluidity

Gupta, Manjari and Krishnamurthy, HR and Freericks, JK (2013) Strong-coupling expansion for ultracold bosons in an optical lattice at finite temperatures in the presence of superfluidity. In: Physical Review A, 88 (5). 053636_1-053636_11.

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Abstract

We develop a strong-coupling (t << U) expansion technique for calculating the density profile for bosonic atoms trapped in an optical lattice with an overall harmonic trap at finite temperature and finite on-site interaction in the presence of superfluid regions. Our results match well with quantum Monte Carlo simulations at finite temperature. We also show that the superfluid order parameter never vanishes in the trap due to the proximity effect. Our calculations for the scaled density in the vacuum-to-superfluid transition agree well with the experimental data for appropriate temperatures. We present calculations for the entropy per particle as a function of temperature which can be used to calibrate the temperature in experiments. We also discuss issues connected with the demonstration of universal quantum critical scaling in the experiments.

Item Type:	Journal Article
Publication:	Physical Review A
Publisher:	American Physical Society
Additional Information:	Copyright of this article belongs to American Physical Society.
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	07 Jan 2014 05:36
Last Modified:	07 Jan 2014 05:36
URI:	http://eprints.iisc.ac.in/id/eprint/48108

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