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

Autor: Maxim Pyzh, Sven Krönke, Christof Weitenberg, Peter Schmelcher
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: New Journal of Physics, Vol 20, Iss 1, p 015006 (2018)
Druh dokumentu: article
ISSN: 1367-2630
DOI: 10.1088/1367-2630/aa9cb2
Popis: We 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.
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