The barriers to producing multiparticle superposition states in rotating Bose–Einstein condensates

Autor: David W. Hallwood, Keith Burnett, Jacob Dunningham
Rok vydání: 2007
Předmět:
Zdroj: Journal of Modern Optics. 54:2129-2148
ISSN: 1362-3044
0950-0340
Popis: We study why it is quite so hard to make a superposition of superfluid flows in a Bose–Einstein condensate. To do this we initially investigate the quantum states of N atoms trapped in a 1D ring with a barrier at one position and a phase applied around it. We show how macroscopic superpositions can in principle be produced and investigate factors which affect the superposition. We then use the Bose–Hubbard model to study an array of Bose–Einstein condensates trapped in optical potentials and coupled to one another to form a ring. We derive analytic expressions for the quality of the superposition for this system, which agrees well with direct diagonalization of the Hamiltonian for relatively small numbers of atoms. We show that for macroscopic superpositions to be realized there are essentially three straightforward requirements, other than an absence of decoherence, which become harder to achieve as the system size increases. Firstly, the energies of the two distinct superfluid states must be sufficientl...
Databáze: OpenAIRE