19,838 research outputs found
Vibration Induced Non-adiabatic Geometric Phase and Energy Uncertainty of Fermions in Graphene
We investigate geometric phase of fermion states under relative vibrations of
two sublattices in graphene by solving time-dependent Sch\"{o}dinger equation
using Floquet scheme. In a period of vibration the fermions acquire different
geometric phases depending on their momenta. There are two regions in the
momentum space: the adiabatic region where the geometric phase can be
approximated by the Berry phase and the chaotic region where the geometric
phase drastically fluctuates in changing parameters. The energy of fermions due
to vibrations shows spikes in the chaotic region. The results suggest a
possible dephasing mechanism which may cause classical-like transport
properties in graphene.Comment: 9 pages, 5 figure
Fantastic Behavior of High-TC Superconductor Junctions: Tunable Superconductivity
Carrier injection performed in oxygen-deficient YBa2Cu3O7(YBCO)
hetero-structure junctions exhibited tunable resistance that was entirely
different with behaviors of semiconductor devices. Tunable superconductivity in
YBCO junctions, increasing over 20 K in transition temperature, has achieved by
using electric processes. To our knowledge, this is the first observation that
intrinsic property of high TC superconductors superconductivity can be adjusted
as tunable functional parameters of devices. The fantastic phenomenon caused by
carrier injection was discussed based on a proposed charge carrier
self-trapping model and BCS theory.Comment: 5 pages, 4 figure
Aqua MODIS Electronic Crosstalk on SMWIR Bands 20 to 26
Aqua MODIS Moon images obtained with bands 20 to 26 (3.66 - 4.55 and 1.36 -
1.39 m) during scheduled lunar events show evidence of electronic
crosstalk contamination of the response of detector 1. In this work, we
determined the sending bands for each receiving band. We found that the
contaminating signal originates, in all cases, from the detector 10 of the
corresponding sending band and that the signals registered by the receiving and
sending detectors are always read out in immediate sequence. We used the lunar
images to derive the crosstalk coefficients, which were then applied in the
correction of electronic crosstalk striping artifacts present in L1B images,
successfully restoring product quality.Comment: Accepted to be published in the IEEE 2017 International Geoscience &
Remote Sensing Symposium (IGARSS 2017), scheduled for July 23-28, 2017 in
Fort Worth, Texas, US
Double potential step chronoamperometry at a microband electrode: Theory and experiment
Numerical simulation is used to characterise double potential step
chronoamperometry at a microband electrode for a simple redox process A + e-
goes to B, under conditions of full support such that diffusion is the only
active form of mass transport. The method is shown to be highly sensitive for
the measurement of the diffusion coefficient of both A and B, and is applied to
the one electron reduction of decamethylferrocene (DMFc), DMFc - e- goes to
DMFc+, in the room temperature ionic liquid 1-propyl-3-methylimidazolium
bistrifluoromethylsulfonylimide. Theory and experiment are seen to be in
excellent agreement and the following values of the diffusion coefficients were
measured at 298 K: D_(DMFc) = 2.50 x 10^(-7) cm^(2) s^(-1) and D_(DMFc+) = 9.50
x 10^(-8) cm^(2) s^(-1)
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