Comparative studies of many-body corrections to an interacting Bose-Einstein condensate

Shohei Watabe, Yoji Ohashi

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

We compare many-body theories describing fluctuation corrections to the mean-field theory in a weakly interacting Bose-condensed gas. Using a generalized random-phase approximation, we include both density fluctuations and fluctuations in the particle-particle scattering channel in a consistent manner. We also separately examine effects of the fluctuations within the framework of the random-phase approximation. Effects of fluctuations in the particle-particle scattering channel are also separately examined by using the many-body T-matrix approximation. We assess these approximations with respect to the transition temperature Tc, the order of phase transition, as well as the so-called Nepomnyashchii-Nepomnyashchii identity, which states the vanishing off-diagonal self-energy in the low-energy and low-momentum limit. Since the construction of a consistent theory for interacting bosons which satisfies various required conditions is a long-standing problem in cold atom physics, our results would be useful for this important challenge.

Original languageEnglish
Article number053633
JournalPhysical Review A - Atomic, Molecular, and Optical Physics
Volume88
Issue number5
DOIs
Publication statusPublished - 2013 Nov 26

Fingerprint

Bose-Einstein condensates
approximation
fluctuation theory
scattering
bosons
transition temperature
momentum
physics
energy
gases
atoms

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this

Comparative studies of many-body corrections to an interacting Bose-Einstein condensate. / Watabe, Shohei; Ohashi, Yoji.

In: Physical Review A - Atomic, Molecular, and Optical Physics, Vol. 88, No. 5, 053633, 26.11.2013.

Research output: Contribution to journalArticle

@article{5967eeb241224297ba453e86a5f28320,
title = "Comparative studies of many-body corrections to an interacting Bose-Einstein condensate",
abstract = "We compare many-body theories describing fluctuation corrections to the mean-field theory in a weakly interacting Bose-condensed gas. Using a generalized random-phase approximation, we include both density fluctuations and fluctuations in the particle-particle scattering channel in a consistent manner. We also separately examine effects of the fluctuations within the framework of the random-phase approximation. Effects of fluctuations in the particle-particle scattering channel are also separately examined by using the many-body T-matrix approximation. We assess these approximations with respect to the transition temperature Tc, the order of phase transition, as well as the so-called Nepomnyashchii-Nepomnyashchii identity, which states the vanishing off-diagonal self-energy in the low-energy and low-momentum limit. Since the construction of a consistent theory for interacting bosons which satisfies various required conditions is a long-standing problem in cold atom physics, our results would be useful for this important challenge.",
author = "Shohei Watabe and Yoji Ohashi",
year = "2013",
month = "11",
day = "26",
doi = "10.1103/PhysRevA.88.053633",
language = "English",
volume = "88",
journal = "Physical Review A",
issn = "2469-9926",
publisher = "American Physical Society",
number = "5",

}

TY - JOUR

T1 - Comparative studies of many-body corrections to an interacting Bose-Einstein condensate

AU - Watabe, Shohei

AU - Ohashi, Yoji

PY - 2013/11/26

Y1 - 2013/11/26

N2 - We compare many-body theories describing fluctuation corrections to the mean-field theory in a weakly interacting Bose-condensed gas. Using a generalized random-phase approximation, we include both density fluctuations and fluctuations in the particle-particle scattering channel in a consistent manner. We also separately examine effects of the fluctuations within the framework of the random-phase approximation. Effects of fluctuations in the particle-particle scattering channel are also separately examined by using the many-body T-matrix approximation. We assess these approximations with respect to the transition temperature Tc, the order of phase transition, as well as the so-called Nepomnyashchii-Nepomnyashchii identity, which states the vanishing off-diagonal self-energy in the low-energy and low-momentum limit. Since the construction of a consistent theory for interacting bosons which satisfies various required conditions is a long-standing problem in cold atom physics, our results would be useful for this important challenge.

AB - We compare many-body theories describing fluctuation corrections to the mean-field theory in a weakly interacting Bose-condensed gas. Using a generalized random-phase approximation, we include both density fluctuations and fluctuations in the particle-particle scattering channel in a consistent manner. We also separately examine effects of the fluctuations within the framework of the random-phase approximation. Effects of fluctuations in the particle-particle scattering channel are also separately examined by using the many-body T-matrix approximation. We assess these approximations with respect to the transition temperature Tc, the order of phase transition, as well as the so-called Nepomnyashchii-Nepomnyashchii identity, which states the vanishing off-diagonal self-energy in the low-energy and low-momentum limit. Since the construction of a consistent theory for interacting bosons which satisfies various required conditions is a long-standing problem in cold atom physics, our results would be useful for this important challenge.

UR - http://www.scopus.com/inward/record.url?scp=84890332772&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84890332772&partnerID=8YFLogxK

U2 - 10.1103/PhysRevA.88.053633

DO - 10.1103/PhysRevA.88.053633

M3 - Article

VL - 88

JO - Physical Review A

JF - Physical Review A

SN - 2469-9926

IS - 5

M1 - 053633

ER -