504 research outputs found
Giant formation rates of ultracold molecules via Feshbach Optimized Photoassociation
Ultracold molecules offer a broad variety of applications, ranging from
metrology to quantum computing. However, forming "real" ultracold molecules,
{\it i.e.} in deeply bound levels, is a very difficult proposition. Here, we
show how photoassociation in the vicinity of a Feshbach resonance enhance
molecular formation rates by several orders of magnitude. We illustrate this
effect in heteronuclear systems, and find giant rate coefficients even in
deeply bound levels. We also give a simple analytical expression for the
photoassociation rates, and discuss future applications of the Feshbach
Optimized Photoassociation, or FOPA, technique
Feshbach-optimized photoassociation of ultracold LiRb molecules with short pulses
Two-color photoassociation of ground state LiRb molecules via the
electronic state using short pulses near a magnetic Feshbach
resonance is studied theoretically. A near-resonant magnetic field is applied
to mix the hyperfine singlet and triplet components of the initial wave
function and enhance the photoassociation rate, before the population is
transferred to the ground state by a second pulse. We show that an increase of
up to three orders of magnitude in the absolute number of molecules produced is
attainable for deeply bound vibrational levels. This technique can be
generalized to other molecules with accessible magnetic Feshbach resonances.Comment: 11 pages, 10 figures; submitted to Phys. Rev.
Phase gate and readout with an atom/molecule hybrid platform
We suggest a combined atomic/molecular system for quantum computation, which
takes advantage of highly developed techniques to control atoms and recent
experimental progress in manipulation of ultracold molecules. We show that two
atoms of different species in a given site, {\it e.g.}, in an optical lattice,
could be used for qubit encoding, initialization and readout, with one atom
carrying the qubit, the other enabling a gate. In particular, we describe how a
two-qubit phase gate can be realized by transferring a pair of atoms into the
ground rovibrational state of a polar molecule with a large dipole moment, and
allowing two molecules to interact via their dipole-dipole interaction. We also
discuss how the reverse process of coherently transferring a molecule into a
pair of atoms could be used as a readout tool for molecular quantum computers
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