Interference of two Bose-Einstein condensates with collisions

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

“…Javanainen and Yoo [14] proposed that the phase of the condensate is established by measurement: an interference pattern is certainly observed in each single experimental run, but the patterns shift from run to run, so that no interference persists if all the observed interference patterns are superimposed, with no contradiction with the common wisdom on the first-order interference. The conclusion that the phenomenon can be ascribed to "measurement-induced interference" was also corroborated by related studies by Cirac et al [15], by Wong et al [16], and by Castin and Dalibard [17]. The main ideas are also explained in review papers [1,3,4] and even in textbooks [6,7], to signify the fundamental importance of the problem and its correct interpretation.…”

Changing quantum reference frames

“…For example, in switching phase or clock reference lasers from a locked laser A to an uncorrelated laser B, one first needs to phase lock the two lasers [2][3][4][5] (this has been extended to issues in optical teleportation [6,7]). In another example, determining the relative phase of two Bose-Einstein condensates [5,[8][9][10][11][12] can be interpreted as correlating quantum reference frames [1,13,14].…”

“…In this paper, we will investigate and quantify how the description of the quantum system S changes as a result of this change of quantum reference frame process. This analysis provides the theoretical description of a process that occurs in numerous experimental guises [1][2][3][4][5][6][7][8][9][10][11][12][13][14], and may also form the first element of a relativity principle for quantum reference frames, which dictates how the description and dynamics of a physical system changes under a change of reference frame.…”

Physics with coherent matter waves

“…The fundamental controvery of major importance concerning the matter wave coherence was if two seperately created condensates would be able to form a visible interference pattern and if this would be consistent with a Fock state description. This controvery was resolved by the experiment described below and the theoretical prediction, that two Fock states can indeed form an interference pattern, when overlapped [87,88,89,90,91,92,93].…”