4,339 research outputs found
Polarized Electric Current in Semiclassical Transport with Spin-Orbit Interaction
Semiclassical solutions of two-dimensional Schrodinger equation with
spin-orbit interaction and smooth potential are considered. In the leading
order, spin polarization is in-plane and follows the evolution of the electron
momentum for a given subband. Out-of-plane spin polarization appears as a
quantum correction, for which an explicit expression is obtained. We
demonstrate how spin-polarized currents can be achieved with the help of a
barrier or quantum point contact open for transmission only in the lower
subband.Comment: 6 pages, 2 figure
Comment on ``Spin and cyclotron energies of electrons in GaAs/GaAlAs quantum wells''
In a recent publication, Pfeffer and Zawadzki [cond-mat/0607150; Phys. Rev. B
74, 115309 (2006)] attempted a calculation of electron g factor in III-V
heterostructures. The authors emphasize that their outcome is in strong
discrepancy with our original result [Ivchenko and Kiselev, Sov. Phys.
Semicond. 26, 827 (1992)] and readily conclude that ``the previous theory of
the g factor in heterostructures is inadequate''. We show here that the entire
discrepancy can be tracked down to an additional contribution missing in the
incomplete elimination procedure of Pfeffer and Zawadzki. This mistake equally
affects their ``exact'' and approximate results. When the overlooked terms
stemming from the nondiagonal Zeeman interaction between light hole and
spin-orbit-split valence states are taken into account in the effective
electron dispersion, the results of the both approaches applied to the
three-level kp model become identical.Comment: 5 pages, no figure
Gold-plated Mode of CP-Violation in Decays of B_c Meson from QCD Sum Rules
The model-independent method based on the triangle ideology is implemented to
extract the CKM-matrix angle gamma in the decays of doubly heavy long-lived
meson B_c. We analyze a color structure of diagrams and conditions to
reconstruct two reference-triangles by tagging the flavor and CP eigenstates of
D^0 meson in the fixed exclusive channels. The characteristic branching ratios
are evaluated in the framework of QCD sum rules.Comment: 11 pages, RevTeX4 file, 4 eps-figure
Global well-posedness for a slightly supercritical surface quasi-geostrophic equation
We use a nonlocal maximum principle to prove the global existence of smooth
solutions for a slightly supercritical surface quasi-geostrophic equation. By
this we mean that the velocity field is obtained from the active scalar
by a Fourier multiplier with symbol , where
is a smooth increasing function that grows slower than as
.Comment: 11 pages, second version with slightly stronger resul
Leptonic constant of pseudoscalar B_c meson
We calculate the leptonic constant for the ground pseudoscalar state of B_c
meson in the framework of QCD-motivated potential model taking into account the
two-loop anomalous dimension for the heavy quark current in the nonrelativistic
QCD as matched with the full QCD.Comment: 6 pages, RevTeX4 file, 3 eps-figures, several references and remarks
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