17,650 research outputs found
Study of timing properties of single gap high-resistive bakelite RPC
The time resolution for several single gap (2 mm) prototype Resistive Plate
Chambers (RPC) made of high resistive (bulk resistivity ~ 10^10 - 10^12 ohm
cm), 2 mm thick matt finished bakelite paper laminates with silicone coating on
the inner surfaces, has been measured. The time resolution for all the modules
has been found to be ~ 2 ns at the plateau region.Comment: 5 figures, Presented in Frontier Detectors for Frontier Physics (11th
Pisa meeting on advanced detectors), La Biodala, Isola d'Elba, Italy, May
24-30, 200
Quantum Computing in Arrays Coupled by 'Always On' Interactions
It has recently been shown that one can perform quantum computation in a
Heisenberg chain in which the interactions are 'always on', provided that one
can abruptly tune the Zeeman energies of the individual (pseudo-)spins. Here we
provide a more complete analysis of this scheme, including several
generalizations. We generalize the interaction to an anisotropic form
(incorporating the XY, or Forster, interaction as a limit), providing a proof
that a chain coupled in this fashion tends to an effective Ising chain in the
limit of far off-resonant spins. We derive the primitive two-qubit gate that
results from exploiting abrupt Zeeman tuning with such an interaction. We also
demonstrate, via numerical simulation, that the same basic scheme functions in
the case of smoothly shifted Zeeman energies. We conclude with some remarks
regarding generalisations to two- and three-dimensional arrays.Comment: 16 pages (preprint format) inc. 3 figure
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