Driven Bose-Hubbard model with a parametrically modulated harmonic trap
Mann, N., Bakhtiari, M. R., Massel, F., Pelster, A., & Thorwart, M. (2017). Driven Bose-Hubbard model with a parametrically modulated harmonic trap. Physical Review A, 95 (4), 043604. doi:10.1103/PhysRevA.95.043604
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Physical Review ADate
2017Copyright
© 2017 American Physical Society. Published in this repository with the kind permission of the publisher.
We investigate a one-dimensional Bose–Hubbard model in a parametrically driven global harmonic trap. The
delicate interplay of both the local interaction of the atoms in the lattice and the driving of the global trap
allows us to control the dynamical stability of the trapped quantum many-body state. The impact of the atomic
interaction on the dynamical stability of the driven quantum many-body state is revealed in the regime of weak
interaction by analyzing a discretized Gross–Pitaevskii equation within a Gaussian variational ansatz, yielding
a Mathieu equation for the condensate width. The parametric resonance condition is shown to be modified
by the atom interaction strength. In particular, the effective eigenfrequency is reduced for growing interaction
in the mean-field regime. For a stronger interaction, the impact of the global parametric drive is determined by
the numerically exact time-evolving block decimation scheme. When the trapped bosons in the lattice are in a
Mott insulating state, the absorption of energy from the driving field is suppressed due to the strongly reduced
local compressibility of the quantum many-body state. In particular, we find that the width of the local Mott
region shows a breathing dynamics. Finally, we observe that the global modulation also induces an effective
time-independent inhomogeneous hopping strength for the atoms.
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