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Title: Laser probing of the single-particle energy gap of a Bose gas in an optical lattice in the Mott-insulator phase

Abstract

We study single-particle excitations of a Bose gas in an optical lattice in the Mott-insulator phase. The characteristic feature of the single-particle spectrum in the Mott-insulator phase is the existence of an energy gap between the particle and hole excitations. We show that the single-particle excitation energies and associated energy gap in the Mott-insulator phase can be directly probed by an output-coupling experiment. We apply the general expression for the output current derived by Luxat and Griffin, which is given in terms of the single-particle Green's functions of a trapped Bose gas, to the Mott-insulator phase using the Bose-Hubbard model. The energy spectrum of the momentum-resolved output current exhibits two characteristic peaks corresponding to the particle and hole excitations, and thus it can be used to detect the transition point from the Mott insulator to superfluid phase where the energy gap disappears.

Authors:
;  [1];  [2]
  1. Department of Physics, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo, 162-8601 (Japan)
  2. Department of Applied Physics, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo, 162-8601 (Japan)
Publication Date:
OSTI Identifier:
20786979
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 73; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevA.73.033621; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; BOSE-EINSTEIN GAS; BOSONS; COUPLING; ELECTRIC CURRENTS; ENERGY GAP; ENERGY SPECTRA; EXCITATION; GREEN FUNCTION; HOLES; HUBBARD MODEL; LASER RADIATION; RADIATION PRESSURE; SUPERFLUIDITY; TRAPPING

Citation Formats

Konabe, S., Nikuni, T., and Nakamura, M. Laser probing of the single-particle energy gap of a Bose gas in an optical lattice in the Mott-insulator phase. United States: N. p., 2006. Web. doi:10.1103/PHYSREVA.73.0.
Konabe, S., Nikuni, T., & Nakamura, M. Laser probing of the single-particle energy gap of a Bose gas in an optical lattice in the Mott-insulator phase. United States. doi:10.1103/PHYSREVA.73.0.
Konabe, S., Nikuni, T., and Nakamura, M. Wed . "Laser probing of the single-particle energy gap of a Bose gas in an optical lattice in the Mott-insulator phase". United States. doi:10.1103/PHYSREVA.73.0.
@article{osti_20786979,
title = {Laser probing of the single-particle energy gap of a Bose gas in an optical lattice in the Mott-insulator phase},
author = {Konabe, S. and Nikuni, T. and Nakamura, M.},
abstractNote = {We study single-particle excitations of a Bose gas in an optical lattice in the Mott-insulator phase. The characteristic feature of the single-particle spectrum in the Mott-insulator phase is the existence of an energy gap between the particle and hole excitations. We show that the single-particle excitation energies and associated energy gap in the Mott-insulator phase can be directly probed by an output-coupling experiment. We apply the general expression for the output current derived by Luxat and Griffin, which is given in terms of the single-particle Green's functions of a trapped Bose gas, to the Mott-insulator phase using the Bose-Hubbard model. The energy spectrum of the momentum-resolved output current exhibits two characteristic peaks corresponding to the particle and hole excitations, and thus it can be used to detect the transition point from the Mott insulator to superfluid phase where the energy gap disappears.},
doi = {10.1103/PHYSREVA.73.0},
journal = {Physical Review. A},
number = 3,
volume = 73,
place = {United States},
year = {Wed Mar 15 00:00:00 EST 2006},
month = {Wed Mar 15 00:00:00 EST 2006}
}
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