### Abstract

The dynamical response of a trapped Bose-Einstein condensate (BEC) is formulated consistently with quantum field theory and is numerically evaluated. We regard the BEC as a manifestation of the breaking of the global phase symmetry. Then, the Goldstone theorem implies the existence of a zero energy excitation mode (the zero-mode). We calculate the effect of the zero-mode on the response frequency and show that the contribution of the zero-mode to the first excitation mode is not so important in the parameter set realized in the existing experiment. This is the reason that experimental results can be described using the Bogoliubov prescription, although it breaks the consistency of the description in quantum field theory.

Original language | English |
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Pages (from-to) | 683-700 |

Number of pages | 18 |

Journal | Progress of Theoretical Physics |

Volume | 115 |

Issue number | 4 |

DOIs | |

Publication status | Published - 2006 Apr |

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### ASJC Scopus subject areas

- Physics and Astronomy(all)

### Cite this

*Progress of Theoretical Physics*,

*115*(4), 683-700. https://doi.org/10.1143/PTP.115.683

**Effect of the zero-mode on the response of a trapped bose-condensed gas.** / Mine, Makoto; Koide, Tomoi; Okumura, Masahiko; Yamanaka, Yoshiya.

Research output: Contribution to journal › Article

*Progress of Theoretical Physics*, vol. 115, no. 4, pp. 683-700. https://doi.org/10.1143/PTP.115.683

}

TY - JOUR

T1 - Effect of the zero-mode on the response of a trapped bose-condensed gas

AU - Mine, Makoto

AU - Koide, Tomoi

AU - Okumura, Masahiko

AU - Yamanaka, Yoshiya

PY - 2006/4

Y1 - 2006/4

N2 - The dynamical response of a trapped Bose-Einstein condensate (BEC) is formulated consistently with quantum field theory and is numerically evaluated. We regard the BEC as a manifestation of the breaking of the global phase symmetry. Then, the Goldstone theorem implies the existence of a zero energy excitation mode (the zero-mode). We calculate the effect of the zero-mode on the response frequency and show that the contribution of the zero-mode to the first excitation mode is not so important in the parameter set realized in the existing experiment. This is the reason that experimental results can be described using the Bogoliubov prescription, although it breaks the consistency of the description in quantum field theory.

AB - The dynamical response of a trapped Bose-Einstein condensate (BEC) is formulated consistently with quantum field theory and is numerically evaluated. We regard the BEC as a manifestation of the breaking of the global phase symmetry. Then, the Goldstone theorem implies the existence of a zero energy excitation mode (the zero-mode). We calculate the effect of the zero-mode on the response frequency and show that the contribution of the zero-mode to the first excitation mode is not so important in the parameter set realized in the existing experiment. This is the reason that experimental results can be described using the Bogoliubov prescription, although it breaks the consistency of the description in quantum field theory.

UR - http://www.scopus.com/inward/record.url?scp=33745785431&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33745785431&partnerID=8YFLogxK

U2 - 10.1143/PTP.115.683

DO - 10.1143/PTP.115.683

M3 - Article

VL - 115

SP - 683

EP - 700

JO - Progress of Theoretical Physics

JF - Progress of Theoretical Physics

SN - 0033-068X

IS - 4

ER -