7,577 research outputs found
Bose-Fermi Mapping and Multi-Branch Spin Chain Model for Strongly Interacting Quantum Gases in One-Dimension: Dynamics and Collective Excitations
We show that the wave function of a one dimensional spinor gas with contact
-wave interaction, either bosonic or fermionic, can be mapped to the direct
product of the wave function of a spinless Fermi gas with short-range -wave
interaction and that of a spin system governed by spin parity projection
operators. Applying this mapping to strongly interacting spinor gases, we
obtain a generalized spin chain model that captures both the static and
dynamics properties of the system. Using this spin chain model, we investigate
the breathing mode frequency and the quench dynamics of strongly interacting
harmonically trapped spinor gases.Comment: 5 pages of main text + 5 pages of Supplemental Materia
Photon-Induced Spin-Orbit Coupling in Ultracold Atoms inside Optical Cavity
We consider an atom inside a ring cavity, where a plane-wave cavity field
together with an external coherent laser beam induces a two-photon Raman
transition between two hyperfine ground states of the atom. This
cavity-assisted Raman transition induces effective coupling between atom's
internal degrees of freedom and its center-of-mass motion. In~the meantime,
atomic dynamics exerts a back-action to cavity photons. We investigate the
properties of this system by adopting a mean-field and a full quantum approach,
and show that the interplay between the atomic dynamics and the cavity field
gives rise to intriguing nonlinear phenomena.Comment: 12 pages, 5 figures, and published versio
Multi-stability in an optomechanical system with two-component Bose-Einstein condensate
We investigate a system consisting of a two-component Bose-Einstein
condensate interacting dispersively with a Fabry-Perot optical cavity where the
two components of the condensate are resonantly coupled to each other by
another classical field. The key feature of this system is that the atomic
motional degrees of freedom and the internal pseudo-spin degrees of freedom are
coupled to the cavity field simultaneously, hence an effective spin-orbital
coupling within the condensate is induced by the cavity. The interplay among
the atomic center- of-mass motion, the atomic collective spin and the cavity
field leads to a strong nonlinearity, resulting in multi- stable behavior in
both matter wave and light wave at the few-photon level.Comment: 4 pages, 3 figure
Strongly Interacting Quantum Gases in One-Dimensional Traps
Under the second-order degenerate perturbation theory, we show that the
physics of particles with arbitrary spin confined in a one dimensional trap
in the strongly interacting regime can be described by super-exchange
interaction. An effective spin-chain Hamiltonian (non-translational-invariant
Sutherland model) can be constructed from this procedure. For spin-1/2
particles, this model reduces to the non-translational-invariant Heisenberg
model, where a transition between Heisenberg anti-ferromagnetic (AFM) and
ferromagnetic (FM) states is expected to occur when the interaction strength is
tuned from the strongly repulsive to the strongly attractive limit. We show
that the FM and the AFM states can be distinguished in two different methods:
the first is based on their distinct response to a spin-dependent magnetic
gradient, and the second is based on their distinct momentum distribution. We
confirm the validity of the spin-chain model by comparison with results
obtained from several unbiased techniquesComment: 14 pages, 7 figure
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