TY - JOUR
T1 - Spontaneous solitons in the thermal equilibrium of a quasi-1D bose gas
AU - Karpiuk, Tomasz
AU - Deuar, Piotr
AU - Bienias, Przemysław
AU - Witkowska, Emilia
AU - Pawłowski, Krzysztof
AU - Gajda, Mariusz
AU - Rzewski, Kazimierz
AU - Brewczyk, Mirosław
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012/11/13
Y1 - 2012/11/13
N2 - We show that solitons occur generically in the thermal equilibrium state of a weakly interacting elongated Bose gas, without the need for external forcing or perturbations. This reveals a major new quality to the experimentally widespread quasicondensate state, usually thought of as primarily phase-fluctuating. Thermal solitons are seen in uniform 1D, trapped 1D, and elongated 3D gases, appearing as shallow solitons at low quasicondensate temperatures, becoming widespread and deep as temperature rises. This behavior can be understood via thermal occupation of the type II excitations in the Lieb-Liniger model of a uniform 1D gas. Furthermore, we find that the quasicondensate phase includes very appreciable density fluctuations while leaving phase fluctuations largely unaltered from the standard picture derived from a density-fluctuation-free treatment.
AB - We show that solitons occur generically in the thermal equilibrium state of a weakly interacting elongated Bose gas, without the need for external forcing or perturbations. This reveals a major new quality to the experimentally widespread quasicondensate state, usually thought of as primarily phase-fluctuating. Thermal solitons are seen in uniform 1D, trapped 1D, and elongated 3D gases, appearing as shallow solitons at low quasicondensate temperatures, becoming widespread and deep as temperature rises. This behavior can be understood via thermal occupation of the type II excitations in the Lieb-Liniger model of a uniform 1D gas. Furthermore, we find that the quasicondensate phase includes very appreciable density fluctuations while leaving phase fluctuations largely unaltered from the standard picture derived from a density-fluctuation-free treatment.
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U2 - 10.1103/PhysRevLett.109.205302
DO - 10.1103/PhysRevLett.109.205302
M3 - Article
C2 - 23215499
AN - SCOPUS:84869072908
VL - 109
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
IS - 20
M1 - 205302
ER -