89 research outputs found
Scalable Ion Trap Quantum Computing without Moving Ions
A hybrid quantum computing scheme is studied where the hybrid qubit is made
of an ion trap qubit serving as the information storage and a solid-state
charge qubit serving as the quantum processor, connected by a superconducting
cavity. In this paper, we extend our previous work [1] and study the
decoherence, coupling and scalability of the hybrid system. We present our
calculations of the decoherence of the coupled ion - charge system due to the
charge fluctuations in the solid-state system and the dissipation of the
superconducting cavity under laser radiation. A gate scheme that exploits rapid
state flips of the charge qubit to reduce decoherence by the charge noise is
designed. We also study a superconducting switch that is inserted between the
cavity and the charge qubit and provides tunable coupling between the qubits.
The scalability of the hybrid scheme is discussed together with several
potential experimental obstacles in realizing this scheme
Remove troops from Fort Gibson
24-1Military AffairsReport on Defense of Arkansas Frontier. [294] Recommends moving troops from Fort Gibson to the Arkansas Frontier.1836-8
Isaac S. Ketchum
28-1Indian AffairsReport : Claim of of I. Ketchum. [446] For provisions furnished Chippewa, Ottawa, and Pottawatomie Indians while they removed west of the Mississippi.1844-7
Non-Fermi-liquid phases in the two-band Hubbard model: Finite-temperature exact diagonalization study of Hund's rule coupling
The two-band Hubbard model involving subbands of different widths is
investigated via finite-temperature exact diagonalization (ED) and dynamical
mean field theory (DMFT). In contrast to the quantum Monte Carlo (QMC) method
which at low temperatures includes only Ising-like exchange interactions to
avoid sign problems, ED permits a treatment of Hund's exchange and other onsite
Coulomb interactions on the same footing. The role of finite-size effects
caused by the limited number of bath levels in this scheme is studied by
analyzing the low-frequency behavior of the subband self-energies as a function
of temperature, and by comparing with numerical renormalization group (NRG)
results for an effective one-band model. For half-filled, non-hybridizing
bands, the metallic and insulating phases are separated by an intermediate
mixed phase with an insulating narrow and a bad-metallic wide subband. The wide
band in this phase exhibits different degrees of non-Fermi-liquid behavior,
depending on the treatment of exchange interactions. Whereas for complete
Hund's coupling, infinite lifetime is found at the Fermi level, in the absence
of spin-flip and pair-exchange, this lifetime becomes finite. Excellent
agreement is obtained both with new NRG and previous QMC/DMFT calculations.
These results suggest that-finite temperature ED/DMFT might be a useful scheme
for realistic multi-band materials.Comment: 15 pages, 17 figure
L. A. Thrasher and Mrs. C. C. Short.
44-1ClaimsReport : Claim of of the Administrator of O. Short. [1709] Cheyenne depredations in Kansas.1876-10
Muon counting using silicon photomultipliers in the AMIGA detector of the Pierre Auger observatory
AMIGA (Auger Muons and Infill for the Ground Array) is an upgrade of the Pierre Auger Observatory designed to extend its energy range of detection and to directly measure the muon content of the cosmic ray primary particle showers. The array will be formed by an infill of surface water-Cherenkov detectors associated with buried scintillation counters employed for muon counting. Each counter is composed of three scintillation modules, with a 10 m(2) detection area per module. In this paper, a new generation of detectors, replacing the current multi-pixel photomultiplier tube (PMT) with silicon photo sensors (aka. SiPMs), is proposed. The selection of the new device and its front-end electronics is explained. A method to calibrate the counting system that ensures the performance of the detector is detailed. This method has the advantage of being able to be carried out in a remote place such as the one where the detectors are deployed. High efficiency results, i.e. 98% efficiency for the highest tested overvoltage, combined with a low probability of accidental counting (~2%), show a promising performance for this new system.Peer Reviewe
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