Interacting trapped bosons yield fragmented condensate states in low dimensions

Journal Article · Thu Jul 15 00:00:00 EDT 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.82.013607· OSTI ID:21442956

Fischer, Uwe R ^[1]; Bader, Philipp ^[2]

---

1. Seoul National University, Department of Physics and Astronomy, Center for Theoretical Physics, 151-747 Seoul (Korea, Republic of)
2. Universidad Politecnica de Valencia, Instituto de Matematica Multidisciplinar, E-46022 Valencia (Spain)

We investigate the level population statistics and degree of coherence encoded in the single-particle density matrix of harmonically trapped low-dimensional [quasi-one-dimensional (quasi-1D) or quasi-two-dimensional (quasi-2D)] Bose gases with repulsive contact interactions. Using a variational analysis, we derive fragmentation of the condensate in the weakly confining directions into two (quasi-1D) and three (quasi-2D) mutually incoherent macroscopic pieces, upon increasing a dimensionless interaction measure beyond a critical value. Fragmented condensate many-body states in low-dimensional systems therefore occur well before the thermodynamic limit of infinite extension is reached, in which phase fluctuations of the matter wave field create an infinite number of nonmacroscopic fragments.

• OSTI ID: 21442956
• Journal Information: Physical Review. A, Vol. 82, Issue 1; Other Information: DOI: 10.1103/PhysRevA.82.013607; (c) 2010 The American Physical Society; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
74 ATOMIC AND MOLECULAR PHYSICS
BOSE-EINSTEIN CONDENSATION
BOSE-EINSTEIN GAS
BOSONS
DENSITY MATRIX
ENERGY LEVELS
FLUCTUATIONS
MANY-BODY PROBLEM
ONE-DIMENSIONAL CALCULATIONS
TRAPPING
TWO-DIMENSIONAL CALCULATIONS
VARIATIONAL METHODS
CALCULATION METHODS
MATRICES
VARIATIONS