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Parallel Magnetic Field (parallel + magnetic_field)

Distribution by Scientific Domains
Physics and Astronomy100%

Selected Abstracts

Aharonov,Bohm effects in multiwall carbon nanotubes

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 13 2006
C. Strunk
Abstract We investigate quantum transport phenomena in multiwall carbon nanotubes in perpendicular and parallel magnetic field. An efficient gating technique allows for a considerable tuning of the nanotube doping level. We show that the weak localization is strongly suppressed at peaks at certain gate voltages which can be linked with the bottoms of one-dimensional electronic subbands. In large parallel magnetic field, we observe a superposition of h /2e -periodic Altshuler-Aronov-Spivak oscillations and an additional h /e -periodic contribution, which we attribute to the magnetic field dependence of the band structure. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Interwell exciton dispersion engineering, coherent phonons generation and optical detection of exciton condensate

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 1 2004
Yu. E. Lozovik
Abstract We propose to use dispersion engineering of interwell excitons in coupled quantum wells with external electric and magnetic fields in order to generate coherent phonons and to detect exciton condensate. A parallel magnetic field moves the dispersion minimum of interwell excitons away from the radiative zone and thus reduces their recombination rate. Normal electric field moves an interwell excitons dispersion minimum on the energy scale. These two fields effect can be used to tune the resonance condition of the interwell excitons recombination process via an in-well excitons level, which results in acoustic phonon emission. We show, that one can change recombination rate as well as intensity and angular distribution of the interwell excitons photoluminescence in the wide range by controlling the external fields. Based on this principle we propose and theoretically evaluate a procedure to detect the condensate of interwell excitons, as well as a scheme to obtain a coherent and monochromatic phonon beam (saser). The statistics of the phonon emission from the condensate of interwell excitons is studied. Numerical estimate for GaAs/AlGaAs coupled quantum wells is provided. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Conductance asymmetry of a slot gate Si-MOSFET in a strong parallel magnetic field

ANNALEN DER PHYSIK, Issue 12 2009
I. Shlimak
Abstract We report measurements on a Si-MOSFET sample with a slot in the upper gate, allowing for different electron densities n1,2 across the slot. The dynamic longitudinal resistance was measured by the standard lock-in technique, while maintaining a large DC current through the source-drain channel. We find that the conductance of the sample in a strong parallel magnetic field is asymmetric with respect to the DC current direction. This asymmetry increases with magnetic field. The results are interpreted in terms of electron spin accumulation or depletion near the slot. [source]