Quantum atom optics with trapped Bose-Einstein condensates

Abstract

Both Bose-Einstein condensates and optical fields are composed of bosons, so that the majority of the processes which have long been studied in quantum and nonlinear optics have equivalents in the field of Bose-Einsten condensation. However, due to the masses of the condensed atoms, the confining potentials and the huge collisional nonlinearities, the simpler theoretical approaches common to quantum optics can sometimes give misleading answers when applied to condensates. In this work we describe some of the areas where simplified treatments can be misleading, and compare and contrast the predictions of quantum many-body treatments with those of the single-mode type treatments which have been so successful in quantum optics.

Dynamics and statistical mechanics of ultra-cold Bose gases using c-field techniques

“…For short times the linewidth was found to be inversely proportional to the output coupling time, a feature adequately described by the GPE. However, on longer timescales the linewidth predictions of the two theories differed: the truncated Wigner simulations plateaued towards the Poissonianlimit (151), whereas the GPE continued to narrow.…”

“…The field of superchemistry was defined by Heinzen et al [92] as "the coherent stimulation of chemical reactions via macroscopic occupation of a quantum state by a bosonic chemical species". Truncated Wigner simulations were used by Olsen et al [151][152][153][154][155] to investigate superchemistry based on photo-association of trapped BECs into molecular dimers. The atom-molecule coupling occurs through a Raman two-photon transition for which the interaction Hamiltonian can be written as [152] whereψ a (x) is the atomic field,ψ m * (x) the excited molecular field, andψ m (x) is the molecular ground state field.…”