585 research outputs found
Quantum Control of Qubits and Atomic Motion Using Ultrafast Laser Pulses
Pulsed lasers offer significant advantages over CW lasers in the coherent
control of qubits. Here we review the theoretical and experimental aspects of
controlling the internal and external states of individual trapped atoms with
pulse trains. Two distinct regimes of laser intensity are identified. When the
pulses are sufficiently weak that the Rabi frequency is much smaller
than the trap frequency \otrap, sideband transitions can be addressed and
atom-atom entanglement can be accomplished in much the same way as with CW
lasers. By contrast, if the pulses are very strong (\Omega \gg \otrap),
impulsive spin-dependent kicks can be combined to create entangling gates which
are much faster than a trap period. These fast entangling gates should work
outside of the Lamb-Dicke regime and be insensitive to thermal atomic motion.Comment: 16 pages, 15 figure
Entanglement of Atomic Qubits using an Optical Frequency Comb
We demonstrate the use of an optical frequency comb to coherently control and
entangle atomic qubits. A train of off-resonant ultrafast laser pulses is used
to efficiently and coherently transfer population between electronic and
vibrational states of trapped atomic ions and implement an entangling quantum
logic gate with high fidelity. This technique can be extended to the high field
regime where operations can be performed faster than the trap frequency. This
general approach can be applied to more complex quantum systems, such as large
collections of interacting atoms or molecules.Comment: 4 pages, 5 figure
Cold Matter Assembled Atom-by-Atom
The realization of large-scale fully controllable quantum systems is an
exciting frontier in modern physical science. We use atom-by-atom assembly to
implement a novel platform for the deterministic preparation of regular arrays
of individually controlled cold atoms. In our approach, a measurement and
feedback procedure eliminates the entropy associated with probabilistic trap
occupation and results in defect-free arrays of over 50 atoms in less than 400
ms. The technique is based on fast, real-time control of 100 optical tweezers,
which we use to arrange atoms in desired geometric patterns and to maintain
these configurations by replacing lost atoms with surplus atoms from a
reservoir. This bottom-up approach enables controlled engineering of scalable
many-body systems for quantum information processing, quantum simulations, and
precision measurements.Comment: 12 pages, 9 figures, 3 movies as ancillary file
Analysis of technology requirements and potential demand for general aviation avionics systems for operation in the 1980's
Avionics systems are identified which promise to reduce economic constraints and provide significant improvements in performance, operational capability and utility for general aviation aircraft in the 1980's
Atom-by-atom assembly of defect-free one-dimensional cold atom arrays
The realization of large-scale fully controllable quantum systems is an exciting frontier in modern physical science. We use atom-by-atom assembly to implement a platform for the deterministic preparation of regular one-dimensional arrays of individually controlled cold atoms. In our approach, a measurement and feedback procedure eliminates the entropy associated with probabilistic trap occupation and results in defect-free arrays of over 50 atoms in less than 400 milliseconds. The technique is based on fast, real-time control of 100 optical tweezers, which we use to arrange atoms in desired geometric patterns and to maintain these configurations by replacing lost atoms with surplus atoms from a reservoir. This bottom-up approach may enable controlled engineering of scalable many-body systems for quantum information processing, quantum simulations, and precision measurements
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