Spectral properties and breathing dynamics of a few-body Bose–Bose mixture in a 1D harmonic trap

Abstract

-Beyond mean-field dynamics of ultra-cold bosonic atoms in higher dimensions: facing the challenges with a multiconfigurational approach V J Bolsinger, S Krönke and P Schmelcher - Recent citationsCorrelation effects in the quench-induced phase separation dynamics of a two species ultracold quantum gas S I Mistakidis et al AbstractWe investigate a few-body mixture of two bosonic components, each consisting of two particles confined in a quasi one-dimensional harmonic trap. By means of exact diagonalization with a correlated basis approach we obtain the low-energy spectrum and eigenstates for the whole range of repulsive intra-and inter-component interaction strengths. We analyse the eigenvalues as a function of the inter-component coupling, covering hereby all the limiting regimes, and characterize the behaviour in-between these regimes by exploiting the symmetries of the Hamiltonian. Provided with this knowledge we study the breathing dynamics in the linear-response regime by slightly quenching the trap frequency symmetrically for both components. Depending on the choice of interactions strengths, we identify 1 to 3 monopole modes besides the breathing mode of the centre of mass coordinate. For the uncoupled mixture each monopole mode corresponds to the breathing oscillation of a specific relative coordinate. Increasing the inter-component coupling first leads to multi-mode oscillations in each relative coordinate, which turn into single-mode oscillations of the same frequency in the composite-fermionization regime.

Correlation effects in the quench-induced phase separation dynamics of a two species ultracold quantum gas

“…Besides the filamentation of its density, each species performs collective oscillations that result in an expansion and contraction of the bosonic cloud. Namely a breathing mode [30,64] possessing a frequency w p = » º W T 2 0 . 2 2 br .…”

Quantum correlations and degeneracy of identical bosons in a two-dimensional harmonic trap

“…An alternative way for counting the degeneracy is by making use of the Fock basis introduced in the previous section, Eq. (11). Those states are eigenstates of H 0 , i.e.,Ĥ…”

“…There are many works studying fermionization in 1D, for instance, in optical lattices [8], in few-atom mixtures [9][10][11], for attractive interactions [12] and for few dipolar bosons [13]. In other cases, the focus are quantum correlations [14,15], its effects in mixtures of distinguishable and identical particles [16] and analytic ansatz to capture the physics in all interaction regimes [17].…”

Entanglement-assisted tunneling dynamics of impurities in a double well immersed in a bath of lattice trapped bosons

“…Apart from varying the external confining potential and its dimensionality [1][2][3], it is also possible to tune the interaction strength between the atoms via Feshbach or confinement induced resonances [4,5]. This exquisite level of control over single component fermionic or bosonic ensembles can be extended to mixtures of ultracold atoms such as Bose-Bose [6][7][8][9][10][11][12][13][14][15][16], Fermi-Fermi [17,18] and Bose-Fermi [19,20] mixtures. In particular, one-dimensional systems exhibit intriguing phenomena since they allow for correlations to appear in the dilute regime [21][22][23][24].…”