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Title: Thermally induced rotons in two-dimensional dilute Bose gases

Abstract

We show that rotonlike excitations are thermally induced in a two-dimensional dilute Bose gas as a consequence of the strong phase fluctuations in two dimensions. At low momentum, the rotonlike excitations lead for small enough temperatures to an anomalous phonon spectrum with a temperature-dependent exponent reminiscent of the Kosterlitz-Thouless transition. Despite the anomalous form of the energy spectrum, it is shown that the corresponding effective theory of vortices describes the usual Kosterlitz-Thouless transition. The possible existence of an anomalous normal state in a small temperature interval is also discussed.

Authors:
;  [1]
  1. Institut fuer Theoretische Physik, Freie Universitaet Berlin, Arnimallee 14, D-14195 Berlin (Germany)
Publication Date:
OSTI Identifier:
20787996
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. B, Condensed Matter and Materials Physics; Journal Volume: 73; Journal Issue: 10; Other Information: DOI: 10.1103/PhysRevB.73.104515; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BOSE-EINSTEIN GAS; BOSONS; ENERGY SPECTRA; EXCITATION; FLUCTUATIONS; PHONONS; ROTONS; TEMPERATURE DEPENDENCE; TWO-DIMENSIONAL CALCULATIONS; VORTICES

Citation Formats

Nogueira, Flavio S., and Kleinert, Hagen. Thermally induced rotons in two-dimensional dilute Bose gases. United States: N. p., 2006. Web. doi:10.1103/PHYSREVB.73.1.
Nogueira, Flavio S., & Kleinert, Hagen. Thermally induced rotons in two-dimensional dilute Bose gases. United States. doi:10.1103/PHYSREVB.73.1.
Nogueira, Flavio S., and Kleinert, Hagen. Wed . "Thermally induced rotons in two-dimensional dilute Bose gases". United States. doi:10.1103/PHYSREVB.73.1.
@article{osti_20787996,
title = {Thermally induced rotons in two-dimensional dilute Bose gases},
author = {Nogueira, Flavio S. and Kleinert, Hagen},
abstractNote = {We show that rotonlike excitations are thermally induced in a two-dimensional dilute Bose gas as a consequence of the strong phase fluctuations in two dimensions. At low momentum, the rotonlike excitations lead for small enough temperatures to an anomalous phonon spectrum with a temperature-dependent exponent reminiscent of the Kosterlitz-Thouless transition. Despite the anomalous form of the energy spectrum, it is shown that the corresponding effective theory of vortices describes the usual Kosterlitz-Thouless transition. The possible existence of an anomalous normal state in a small temperature interval is also discussed.},
doi = {10.1103/PHYSREVB.73.1},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
number = 10,
volume = 73,
place = {United States},
year = {Wed Mar 01 00:00:00 EST 2006},
month = {Wed Mar 01 00:00:00 EST 2006}
}