Quasi-Nambu-Goldstone Modes in Bose-Einstein Condensates

Journal Article · Fri Dec 03 00:00:00 EST 2010 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.105.230406· OSTI ID:21554431

Uchino, Shun ^[1]; Kobayashi, Michikazu ^[2]; Nitta, Muneto ^[3]; Ueda, Masahito ^[1]

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1. Department of Physics, University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033 (Japan)
2. Department of Basic Science, University of Tokyo, 3-8-1 Komaba, Tokyo 153-8902 (Japan)
3. Department of Physics, and Research and Education Center for Natural Sciences, Keio University, 4-1-1 Hiyoshi, Kanagawa 223-8521 (Japan)

We show that quasi-Nambu-Goldstone (NG) modes, which play prominent roles in high energy physics but have been elusive experimentally, can be realized with atomic Bose-Einstein condensates. The quasi-NG modes emerge when the symmetry of a ground state is larger than that of the Hamiltonian. When they appear, the conventional vacuum manifold should be enlarged. Consequently, topological defects that are stable within the conventional vacuum manifold become unstable and decay by emitting the quasi-NG modes. Contrary to conventional wisdom, however, we show that the topological defects are stabilized by quantum fluctuations that make the quasi-NG modes massive, thereby suppressing their emission.

• OSTI ID: 21554431
• Journal Information: Physical Review Letters, Vol. 105, Issue 23; Other Information: DOI: 10.1103/PhysRevLett.105.230406; (c) 2010 American Institute of Physics; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BOSE-EINSTEIN CONDENSATION
DECAY
DEFECTS
EMISSION
FLUCTUATIONS
GROUND STATES
HAMILTONIANS
SYMMETRY
TOPOLOGY
ENERGY LEVELS
MATHEMATICAL OPERATORS
MATHEMATICS
QUANTUM OPERATORS
VARIATIONS