Fragmentation of Bose-Einstein Condensates

By E. Mueller, T. Ho, Masahito Ueda, G. Baym. 2006

200 citations recorded by the source corpus.

We present the theory of bosonic systems with multiple condensates, providing a unified description of various model systems that are found in the literature. We discuss how degeneracies, interactions, and symmetries conspire to give rise to this unusual behavior. We show that as degeneracies multiply, so do the varieties of fragmentation, eventually leading to strongly correlated states with no trace of condensation.

Subfields: Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/a82a92844402606ca1e382645f37c72a4279a34e

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In Atomic and Molecular Physics, and Optics

Citations in the corpus

Quantum turbulence in trapped atomic Bose-Einstein condensates (2015, background): “Moreover, there are situations where fragmentation is known to appear in the ground state of trapped gases, as for instance in spinor BECs [211, 212].”
Spinor Bose-Einstein condensates (2010, result): “are equally populated: hˆa† 1 ˆa1i = hˆa † 0 ˆa0i = hˆa † −1aˆ−1i = N 3 . (405) That is, the condensate is fragmented in the sense that more than one single-particle state is macroscopically occupied [132, 4, 86, 133]. This is in sharp contrast with the mean-ﬁeld result that predicts that for c1 &gt”
One dimensional bosons: From condensed matter systems to ultracold gases (2011, background): “When there are several such eigenvalues one speaks of a ‘fragmented’ BEC (see Mueller et al. (2006) and references therein).”
Orbital superfluidity in the $P$-band of a bipartite optical square lattice (2010, background): “[26] suggest that for globally degenerate condensation points, as realized in our experiment for α = αiso, a coexistence scenario with its excess tunneling energy at the phase boundaries is energetically unfavorable for small repulsive interactions, although a stringent theoretical proof is yet an o”
Comparing and contrasting nuclei and cold atomic gases (2013, background): “Even rather strong two-body interactions would not destroy the BEC structure reached for large N (Mueller et al. 2006, Thøgersen et al. 2007).”
Topological bands for ultracold atoms (2018, unknown): “For noninteracting particles, there is a macroscopic degeneracy associated with the occupation of these q degenerate single-particle states: a BEC could form in any linear superposition of these states; or indeed a “fragmented” condensate could form (Mueller et al., 2006).”