218 research outputs found
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Nyi shar Love Song 2
This song is sung to court a potential spouse.
在会场上对有可能性的恋人唱这首歌。This collection contains four dancing songs, two debating songs, nine folk songs, three love songs, and three weddings songs collected in Nyi shar Village, Rgyal thang Town, Rgyal thang County, Bde chen Tibetan Autonomous Prefecture, Yunnan Province, PR China
Anomalous Hall Effect in Ferromagnetic Semiconductors in the Hopping Transport Regime
We present a theory of the Anomalous Hall Effect (AHE) in ferromagnetic
(Ga,Mn)As in the regime when conduction is due to phonon-assisted hopping of
holes between localized states in the impurity band. We show that the
microscopic origin of the anomalous Hall conductivity in this system can be
attributed to a phase that a hole gains when hopping around closed-loop paths
in the presence of spin-orbit interactions and background magnetization of the
localized Mn moments. Mapping the problem to a random resistor network, we
derive an analytic expression for the macroscopic anomalous Hall conductivity
. We show that is proportional to the
first derivative of the density of states and thus can be
expected to change sign as a function of impurity band filling. We also show
that depends on temperature as the longitudinal conductivity
within logarithmic accuracy.Comment: 4 pages, 1 eps figure, final versio
Current percolation and anisotropy in polycrystalline MgB
The influence of anisotropy on the transport current in MgB
polycrystalline bulk samples and wires is discussed. A model for the critical
current density is proposed, which is based on anisotropic London theory, grain
boundary pinning and percolation theory. The calculated currents agree
convincingly with experimental data and the fit parameters, especially the
anisotropy, obtained from percolation theory agree with experiment or
theoretical predictions.Comment: 5 pages, accepted for publication in Physical Review Letters
(http://prl.aps.org/
Superfluid-insulator transition and BCS-BEC crossover in dirty ultracold Fermi gas
Superfluid-insulator transition in an ultracold Fermi gas in the external
disorder potential of the amplitude is studied as a function of the
concentration of the gas and magnetic field in the presence of the
Feshbach resonance. We find the zero temperature phase diagrams in the plane
() at a given and in the plane at a given . Our
results for BEC side of the diagram are also valid for the superfluid-insulator
transition in a Bose gas.Comment: Reference added, typos correcte
Spin-Orbit Assisted Variable-Range Hopping in Strong Magnetic Fields
It is shown that in the presence of strong magnetic fields, spin-orbit
scattering causes a sharp increase in the effective density of states in the
variable-range hopping regime when temperature decreases. This effect leads to
an exponential enhancement of the conductance above its value without
spin-orbit scattering. Thus an experimental study of the hopping conductivity
in a fixed, large magnetic field, is a sensitive tool to explore the spin-orbit
scattering parameters in the strongly localized regime.Comment: 9 pages + 2 figures (enclosed), Revte
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