Interference in a two-mode Bose system as a typical phenomenon

Abstract

When a Bose-Einstein condensate is divided into two parts, that are subsequently released and overlap, interference fringes are observed. We show here that this interference is typical, in the sense that most wave functions of the condensate, randomly sampled out of a suitable ensemble, display interference. We make no hypothesis of decoherence between the two parts of the condensates.

Phase randomization and typicality in the interference of two condensates

“…We observe that similar conclusions are obtained when one deals with plane waves rather than Gaussian modes, 25 the only di®erence being in the coe±cients C i;j in Eq. (24).…”

“…We have shown in Ref. 25 and in this paper that the interference of two independently prepared BECs is typical, namely (almost) always occurs when two BECs are created and let to interfere. This interference is not of¯rst order.…”

“…If the integrals appearing in (25) are equal (e.g. if the mode density pro¯les are related by translation and/or re°ection), the Hamiltonian reduces tô…”

“…We analyzed the interference of a two-mode Bose-Einstein system according to these ideas and showed that some features of the interference pattern (such as its period and its fringe contrast) are robust against both the afore-mentioned°uctuations, 25 and thus ðÁAÞ 2 % n ¼ oðA 2 Þ. We shall summarize the main results in the following sections and shall comment on the role of ðÁAÞ 2 % n for an interesting observable, the power spectrum of particle density.…”

Bound state in the continuum by spatially separated ensembles of atoms in a coupled-cavity array

“…A difficulty is a lack of quantum systems processing such a kind of bound states in general. However, recent investigations in waveguide QED have found interesting examples of BICs for dressed photon-atom systems [17][18][19][20][21][22][23][24]. Waveguide QED generally refers to photon-atom interactions in one-dimensional photonic structures, such as superconducting qubits in transmission lines [25,26], and trapped atoms in a nanophotonic waveguide [27,28].…”