97 research outputs found
Mode coupling of interaction quenched ultracold few-boson ensembles in periodically driven lattices
The out-of-equilibrium dynamics of interaction quenched finite ultracold
bosonic ensembles in periodically driven one-dimensional optical lattices is
investigated. It is shown that periodic driving enforces the bosons in the
outer wells of the finite lattice to exhibit out-of-phase dipole-like modes,
while in the central well the atomic cloud experiences a local breathing mode.
The dynamical behavior is investigated with varying driving frequency,
revealing a resonant-like behavior of the intra-well dynamics. An interaction
quench in the periodically driven lattice gives rise to admixtures of different
excitations in the outer wells, an enhanced breathing in the center and an
amplification of the tunneling dynamics. We observe then multiple resonances
between the inter- and intra-well dynamics at different quench amplitudes, with
the position of the resonances being tunable via the driving frequency. Our
results pave the way for future investigations on the use of combined driving
protocols in order to excite different inter- and intra-well modes and to
subsequently control them.Comment: 18 pages, 12 figure
Phase Separation Dynamics Induced by an Interaction Quench of a Correlated Fermi-Fermi Mixture in a Double Well
We explore the interspecies interaction quench dynamics of ultracold
spin-polarized few-body mass balanced Fermi-Fermi mixtures confined in a
double-well with an emphasis on the beyond Hartree-Fock correlation effects. It
is shown that the ground state of particle imbalanced mixtures exhibits a
symmetry breaking of the single-particle density for strong interactions in the
Hartree-Fock limit, which is altered within the many-body approach. Quenching
the interspecies repulsion towards the strongly interacting regime the two
species phase separate within the Hartree-Fock approximation while remaining
miscible in the many-body treatment. Despite their miscible character on the
one-body level the two species are found to be strongly correlated and exhibit
a phase separation on the two-body level that suggests the anti-ferromagnetic
like behavior of the few-body mixture. For particle balanced mixtures we show
that an intrawell fragmentation (filamentation) of the density occurs both for
the ground state as well as upon quenching from weak to strong interactions, a
result that is exclusively caused by the presence of strong correlations.
Inspecting the two-body correlations a phase separation of the two species is
unveiled being a precursor towards an anti-ferromagnetic state. Finally, we
simulate in-situ single-shot measurements and showcase how our findings can be
retrieved by averaging over a sample of single-shot images.Comment: 15 pages, 9 figure
Many-Body Expansion Dynamics of a Bose-Fermi Mixture Confined in an Optical Lattice
We unravel the correlated non-equilibrium dynamics of a mass balanced
Bose-Fermi mixture in a one-dimensional optical lattice upon quenching an
imposed harmonic trap from strong to weak confinement. Regarding the system's
ground state, the competition between the inter and intraspecies interaction
strength gives rise to the immiscible and miscible phases characterized by
negligible and complete overlap of the constituting atomic clouds respectively.
The resulting dynamical response depends strongly on the initial phase and
consists of an expansion of each cloud and an interwell tunneling dynamics. For
varying quench amplitude and referring to a fixed phase a multitude of response
regimes is unveiled, being richer within the immiscible phase, which are
described by distinct expansion strengths and tunneling channels.Comment: 13 pages, 7 figure
Quantum dynamical response of ultracold few boson ensembles in finite optical lattices to multiple interaction quenches
The correlated non-equilibrium quantum dynamics following a multiple
interaction quench protocol for few-bosonic ensembles confined in finite
optical lattices is investigated. The quenches give rise to an interwell
tunneling and excite the cradle and a breathing mode. Several tunneling
pathways open during the time interval of increased interactions, while only a
few occur when the system is quenched back to its original interaction
strength. The cradle mode, however, persists during and in between the
quenches, while the breathing mode possesses dinstinct frequencies. The
occupation of excited bands is explored in detail revealing a monotonic
behavior with increasing quench amplitude and a non-linear dependence on the
duration of the application of the quenched interaction strength. Finally, a
periodic population transfer between momenta for quenches of increasing
interaction is observed, with a power-law frequency dependence on the quench
amplitude. Our results open the possibility to dynamically manipulate various
excited modes of the bosonic system.Comment: 13 pages, 9 figure
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