Effect of disorder on the interacting fermi gases in a one-dimensional optical lattice
Date
2008Source Title
Condensed Matter Theories
Print ISSN
0217-9792
Electronic ISSN
1793-6578
Publisher
World Scientific Publishing Co.
Volume
23
Pages
212 - 222
Language
English
Type
ArticleItem Usage Stats
288
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views
218
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downloads
Abstract
Interacting two-component Fermi gases loaded in a one-dimensional (1D) lattice and subjected to a harmonic trapping potential exhibit interesting compound phases in which fluid regions coexist with local Mott-insulator and/or band-insulator regions. Motivated by experiments on cold atoms inside disordered optical lattices, we present a theoretical study of the effects of a correlated random potential on these ground-state phases. We employ a lattice version of density-functional theory within the local-density approximation to determine the density distribution of fermions in these phases. The exchange-correlation potential is obtained from the Lieb-Wu exact solution of Fermi-Hubbard model. On-site disorder (with and without Gaussian correlations) and harmonic trap are treated as external potentials. We find that disorder has two main effects: (i) it destroys the local insulating regions if it is suffciently strong compared with the on-site atom-atom repulsion, and (ii) it induces an anomaly in the inverse compressibility at low density from quenching of percolation. For suffciently large disorder correlation length the enhancement in the inverse compressibility diminishes.
Keywords
DisorderFermi-Hubbard model
Optical lattices
Atoms
Compressibility
Crystal lattices
Density functional theory
Electron gas
Fermions
Ground state
Hubbard model
Lattice theory
Local density approximation
Optical materials
Solvents
Correlation lengths
Density distributions
Disorder
Exchange-correlation potential
Gaussian correlation
Harmonic trapping potential
Inverse compressibility
One dimensional optical lattice
Optical lattices
Permalink
http://hdl.handle.net/11693/37830Published Version (Please cite this version)
http://dx.doi.org/10.1142/9789812836625_0022Collections
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