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Title: Finite-momentum Bose-Einstein condensates in shaken two-dimensional square optical lattices

Abstract

We consider ultracold bosons in a two-dimensional square optical lattice described by the Bose-Hubbard model. In addition, an external time-dependent sinusoidal force is applied to the system, which shakes the lattice along one of the diagonals. The effect of the shaking is to renormalize the nearest-neighbor-hopping coefficients, which can be arbitrarily reduced, can vanish, or can even change sign, depending on the shaking parameter. Therefore, it is necessary to account for higher-order-hopping terms, which are renormalized differently by the shaking, and to introduce anisotropy into the problem. We show that the competition between these different hopping terms leads to finite-momentum condensates with a momentum that may be tuned via the strength of the shaking. We calculate the boundaries between the Mott insulator and the different superfluid phases and present the time-of-flight images expected to be observed experimentally. Our results open up possibilities for the realization of bosonic analogs of the Fulde, Ferrel, Larkin, and Ovchinnikov phase describing inhomogeneous superconductivity.

Authors:
 [1];  [2]; ;  [1];  [3];  [2]
  1. Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, NL-3584CE Utrecht (Netherlands)
  2. (Italy)
  3. Department of Physics, University of Catania (Italy)
Publication Date:
OSTI Identifier:
22051348
Resource Type:
Journal Article
Journal Name:
Physical Review. A
Additional Journal Information:
Journal Volume: 84; Journal Issue: 1; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1050-2947
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; BOSE-EINSTEIN CONDENSATION; BOSONS; HUBBARD MODEL; RENORMALIZATION; SUPERCONDUCTIVITY; SUPERFLUIDITY; TIME DEPENDENCE; TIME-OF-FLIGHT METHOD; TWO-DIMENSIONAL CALCULATIONS

Citation Formats

Di Liberto, M., Scuola Superiore di Catania, Universita di Catania, Via Valdisavoia 9, I-95123 Catania, Tieleman, O., Smith, C. Morais, Branchina, V., and INFN, Sezione di Catania, Via Santa Sofia 64, I-95123 Catania. Finite-momentum Bose-Einstein condensates in shaken two-dimensional square optical lattices. United States: N. p., 2011. Web. doi:10.1103/PHYSREVA.84.013607.
Di Liberto, M., Scuola Superiore di Catania, Universita di Catania, Via Valdisavoia 9, I-95123 Catania, Tieleman, O., Smith, C. Morais, Branchina, V., & INFN, Sezione di Catania, Via Santa Sofia 64, I-95123 Catania. Finite-momentum Bose-Einstein condensates in shaken two-dimensional square optical lattices. United States. doi:10.1103/PHYSREVA.84.013607.
Di Liberto, M., Scuola Superiore di Catania, Universita di Catania, Via Valdisavoia 9, I-95123 Catania, Tieleman, O., Smith, C. Morais, Branchina, V., and INFN, Sezione di Catania, Via Santa Sofia 64, I-95123 Catania. Fri . "Finite-momentum Bose-Einstein condensates in shaken two-dimensional square optical lattices". United States. doi:10.1103/PHYSREVA.84.013607.
@article{osti_22051348,
title = {Finite-momentum Bose-Einstein condensates in shaken two-dimensional square optical lattices},
author = {Di Liberto, M. and Scuola Superiore di Catania, Universita di Catania, Via Valdisavoia 9, I-95123 Catania and Tieleman, O. and Smith, C. Morais and Branchina, V. and INFN, Sezione di Catania, Via Santa Sofia 64, I-95123 Catania},
abstractNote = {We consider ultracold bosons in a two-dimensional square optical lattice described by the Bose-Hubbard model. In addition, an external time-dependent sinusoidal force is applied to the system, which shakes the lattice along one of the diagonals. The effect of the shaking is to renormalize the nearest-neighbor-hopping coefficients, which can be arbitrarily reduced, can vanish, or can even change sign, depending on the shaking parameter. Therefore, it is necessary to account for higher-order-hopping terms, which are renormalized differently by the shaking, and to introduce anisotropy into the problem. We show that the competition between these different hopping terms leads to finite-momentum condensates with a momentum that may be tuned via the strength of the shaking. We calculate the boundaries between the Mott insulator and the different superfluid phases and present the time-of-flight images expected to be observed experimentally. Our results open up possibilities for the realization of bosonic analogs of the Fulde, Ferrel, Larkin, and Ovchinnikov phase describing inhomogeneous superconductivity.},
doi = {10.1103/PHYSREVA.84.013607},
journal = {Physical Review. A},
issn = {1050-2947},
number = 1,
volume = 84,
place = {United States},
year = {2011},
month = {7}
}