Goldstone theorem, Hugenholtz-Pines theorem, and Ward-Takahashi relation in finite volume Bose-Einstein condensed gases
- Department of Physics, Waseda University, Tokyo 169-8555 (Japan)
- Department of Applied Physics, Waseda University, Tokyo 169-8555 (Japan)
- Department of Materials Science and Engineering, Waseda University, Tokyo 169-8555 (Japan)
We construct an approximate scheme based on the concept of the spontaneous symmetry breakdown, satisfying the Goldstone theorem, for finite volume Bose-Einstein condensed gases in both zero and finite temperature cases. In this paper, we discuss the Bose-Einstein condensation in a box with periodic boundary condition and do not assume the thermodynamic limit. When energy spectrum is discrete, we found that it is necessary to deal with the Nambu-Goldstone mode explicitly without the Bogoliubov's prescription, in which zero-mode creation- and annihilation-operators are replaced with a c-number by hand, for satisfying the Goldstone theorem. Furthermore, we confirm that the unitarily inequivalence of vacua in the spontaneous symmetry breakdown is true for the finite volume system.
- OSTI ID:
- 20845973
- Journal Information:
- Annals of Physics (New York), Vol. 321, Issue 8; Other Information: DOI: 10.1016/j.aop.2005.12.009; PII: S0003-4916(05)00294-0; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-4916
- Country of Publication:
- United States
- Language:
- English
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