941 research outputs found
Realization of quantum walks with negligible decoherence in waveguide lattices
Quantum random walks are the quantum counterpart of classical random walks, and were recently studied in the context of quantum computation. Physical implementations of quantum walks have only been made in very small scale systems severely limited by decoherence. Here we show that the propagation of photons in waveguide lattices, which have been studied extensively in recent years, are essentially an implementation of quantum walks. Since waveguide lattices are easily constructed at large scales and display negligible decoherence, they can serve as an ideal and versatile experimental playground for the study of quantum walks and quantum algorithms. We experimentally observe quantum walks in large systems (similar to 100 sites) and confirm quantum walks effects which were studied theoretically, including ballistic propagation, disorder, and boundary related effects
Effect of Nonlinearity on Adiabatic Evolution of Light
We investigate the effect of nonlinearity in a system described by an adiabatically evolving Hamiltonian. Experiments are conducted in a three-core waveguide structure that is adiabatically varying with distance, in analogy to the stimulated Raman adiabatic passage process in atomic physics. In the linear regime, the system exhibits an adiabatic power transfer between two waveguides which are not directly coupled, with negligible power recorded in the intermediate coupling waveguide. In the presence of nonlinearity the adiabatic light passage is found to critically depend on the excitation power. We show how this effect is related to the destruction of the dark state formed in this configuration
MiniBooNE
The physics motivations, design, and status of the Booster Neutrino
Experiment at Fermilab, MiniBooNE, are briefly discussed. Particular emphasis
is given on the ongoing preparatory work that is needed for the MiniBooNE muon
neutrino to electron neutrino oscillation appearance search. This search aims
to confirm or refute in a definitive and independent way the evidence for
neutrino oscillations reported by the LSND experiment.Comment: 3 pages, no figures, to appear in the proceedings of the 9th
International Conference on Astroparticle and Underground Physics (TAUP
2005), Zaragoza, Spain, 10-14 Sep 200
Low loss Ge-on-Si waveguides operating in the 8–14 µm atmospheric transmission window
Germanium-on-silicon waveguides were modeled, fabricated and characterized at wavelengths ranging from 7.5 to 11 µm. Measured waveguide losses are below 5 dB/cm for both TE and TM polarization and reach values of ∼ 1 dB/cm for ≥ 10 µm wavelengths for the TE polarization. This work demonstrates experimentally for the first time that Ge-on-Si is a viable waveguide platform for sensing in the molecular fingerprint spectral region. Detailed modeling and analysis is presented to identify the various loss contributions, showing that with practical techniques losses below 1 dB/cm could be achieved across the full measurement range
Cosmo MSW effect for mass varying neutrinos
We consider neutrinos with varying masses which arise in scenarios relating
neutrino masses to the dark energy density in the universe. We point out that
the neutrino mass variation can lead to level crossing and thus a cosmo MSW
effect, having dramatic consequences for the flavor ratio of astrophysical
neutrinos.Comment: 8 pages, 1 figure, more detailed discussions, version to be published
by Mod. Phys. Lett.
Realization of quantum walks with negligible decoherence in waveguide lattices
Quantum random walks are the quantum counterpart of classical random walks, and were recently studied in the context of quantum computation. Physical implementations of quantum walks have only been made in very small scale systems severely limited by decoherence. Here we show that the propagation of photons in waveguide lattices, which have been studied extensively in recent years, are essentially an implementation of quantum walks. Since waveguide lattices are easily constructed at large scales and display negligible decoherence, they can serve as an ideal and versatile experimental playground for the study of quantum walks and quantum algorithms. We experimentally observe quantum walks in large systems (similar to 100 sites) and confirm quantum walks effects which were studied theoretically, including ballistic propagation, disorder, and boundary related effects
Nuclear effects in electron reactions and their impact on neutrino processes
We suggest that superscaling in electroweak interactions with nuclei, namely
the observation that the reduced electron-nucleus cross sections are to a large
degree independent of the momentum transfer and of the nuclear species, can be
used as a tool to obtain precise predictions for neutrino-nucleus cross
sections in both charged and neutral current-induced processes.Comment: 11 pages, 7 figures, proceedings of NUINT09, 6th International
Workshop of Neutrino-Nucleus Interactions in the Few-Gev Region, Sitges
(Spain), May 18-22, 200
Solar panels as air Cherenkov detectors for extremely high energy cosmic rays
Increasing interest towards the observation of the highest energy cosmic rays
has motivated the development of new detection techniques. The properties of
the Cherenkov photon pulse emitted in the atmosphere by these very rare
particles indicate low-cost semiconductor detectors as good candidates for
their optical read-out.
The aim of this paper is to evaluate the viability of solar panels for this
purpose. The experimental framework resulting from measurements performed with
suitably-designed solar cells and large conventional photovoltaic areas is
presented.
A discussion on the obtained and achievable sensitivities follows.Comment: 6 pages, 8 eps figures included with epsfig, uses espcrc2.sty. Talk
given at the Sixth Topical Seminar on Neutrino and Astroparticle Physics, San
Miniato, Italy, 17-21 May 199
Experiment Simulation Configurations Used in DUNE CDR
The LBNF/DUNE CDR describes the proposed physics program and experimental
design at the conceptual design phase. Volume 2, entitled The Physics Program
for DUNE at LBNF, outlines the scientific objectives and describes the physics
studies that the DUNE collaboration will perform to address these objectives.
The long-baseline physics sensitivity calculations presented in the DUNE CDR
rely upon simulation of the neutrino beam line, simulation of neutrino
interactions in the far detector, and a parameterized analysis of detector
performance and systematic uncertainty. The purpose of this posting is to
provide the results of these simulations to the community to facilitate
phenomenological studies of long-baseline oscillation at LBNF/DUNE.
Additionally, this posting includes GDML of the DUNE single-phase far detector
for use in simulations. DUNE welcomes those interested in performing this work
as members of the collaboration, but also recognizes the benefit of making
these configurations readily available to the wider community.Comment: 9 pages, 4 figures, configurations in ancillary file
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