Momentum correlations of a few ultracold bosons escaping from an open well

Abstract

The dynamical properties of a one-dimensional system of two and three bosons escaping from an open potential well are studied in terms of the momentum distributions of particles. In the case of a two-boson system, it is shown that the single-and two-particle momentum distributions undergo a specific transition as the interaction strength is tuned through the point where tunneling switches from the pair tunneling to the sequential one. Characteristic features in the momentum spectra can be used to quantitatively determine the participation of specific decay processes. A corresponding analysis is also performed for the three-boson system, showing a scheme for generalizations to higher particle numbers. For completeness, the time-dependent Tan's contact of the system is also examined and its dynamics is found to undergo a similar transition. The results provide insight into the dynamics of decaying few-body systems and offer potential interest for experimental research. arXiv:1902.03069v3 [cond-mat.quant-gas]

Decay properties of unstable Tonks-Girardeau gases from a split trap

“…First, we shed some light on the effect of a split barrier on the decay properties of one particle being initially in the lowest energy state, Eq. (25). Our results are shown in Fig.…”

“…New advance in experimental techniques has provided the opportunities to study tunnelling phenomena in a controllable way [20][21][22], which has accelerated research activity towards a better understanding of the properties of unstable manybody states. For instance, the recent studies include systems of two identical non-interacting particles [23], ultracold atom systems [24][25][26][27][28][29][30][31], two-particle systems with Coulomb interactions [32] and a model system consisting of a core-nucleus and two valence protons [33]. It is worth mentioning that the complex scaling method [34] also provides a tool for studying the resonance states of many-particle systems [35][36][37][38].…”

One-dimensional mixtures of several ultracold atoms: a review

“…where V 0 and α are controlled experimentally while ξ is the dimensionless position, was deeply studied in [388] and [389]. Finally, the decay problem for attractively interacting bosons was analyzed recently in [390,391]. In these works, it was shown that, depending on the attraction strength, different tunneling processes dominate in the dynamics of the system.…”

Full counting statistics of the momentum occupation numbers of the Tonks-Girardeau gas

“…For example, perfect correlations between opposite momenta, was predicted by Bogoliubov theory in weakly interacting systems [9] and identified to be a hallmark of Bose-Einstein condensation [17,18]. Among others, correlations in momentum space have be shown to be useful for analyzing phenomena such as dynamical Casimir effect [19], Hawking radiation [20][21][22][23][24] or the escape from a barrier [25]. In this paper, we study the fluctuations of the momentum occupation number np in a gas of one-dimensional bosons in the Tonks-Girardeau limit at zero and finite temperature in a harmonic trap.…”

“…This is why the community is now studying higher moments of the momentum occupation number, like its variance N 2 p − N p 2 , covariance N p N q [11][12][13][14][15] or even the full distribution (full counting statistics) [14]. This can be a great help for unraveling different regimes [11,16,17] or to identify exotic phenomena like the dynamical Casimir effect [18] or Hawking radiation for instance [19][20][21][22][23]. The data represent a single shot measurement whereas the full line is the average Np .…”