相关论文: Magnetoresistance Induced by Rare Strong Scatterer…
In a high mobility two-dimensional electron gas (2DEG) in a GaAs/AlGaAs quantum well we observe a strong magnetoresistance. In lowering the electron density the magnetoresistance gets more pronounced and reaches values of more than 300%. We…
We present magnetotransport results for a 2D electron gas (2DEG) subject to the quasi-random magnetic field produced by randomly positioned sub-micron Co dots deposited onto the surface of a GaAs/AlGaAs heterostructure. We observe strong…
In high-mobility two-dimensional electron gases Landau levels are already formed at very small magnetic field values. Such two-dimensional electron gases show a huge negative magnetoresistance at low temperatures and an unexpected and very…
We report magnetoresistance measurements on a two-dimensional electron gas (2DEG) made from a high mobility GaAs/AlGaAs heterostructure, where the externally applied magnetic field was expelled from regions of the semiconductor by means of…
We have observed a large positive quasi-classical magneto-resistance (MR) in a high mobility 2D electron gas in AlGaAs/GaAs heterostructure. The magneto-resistance is non-saturating and increases with magnetic field as $\rho_{xx}\sim…
The effect of a spatially modulated magnetic field on the weak localization phenomenon in two-dimensional electron gas (2DEG) is studied. Both the dephasing time $\tau_H$ and magnetoresistance are shown to reveal a nontrivial behavior as…
We study the quasiclassical magnetotransport of non-interacting fermions in two dimensions moving in a random array of strong scatterers (antidots, impurities or defects) on the background of a smooth random potential. We demonstrate that…
We report on a giant negative magnetoresistance in very high mobility GaAs/AlGaAs heterostructures and quantum wells. The effect is the strongest at $B \simeq 1$ kG, where the magnetoresistivity develops a minimum emerging at $T \lesssim 2$…
Considering the quantum dynamics of 2DEG exposed to both a stationary magnetic field and an intense high-frequency electromagnetic wave, we found that the wave decreases the scattering-induced broadening of Landau levels. Therefore, various…
The unsymmetric confinement of the electrons in a typical 2-dimensional electron gas (2DEG) breaks the full cubic symmetry of the in-plane transport properties. A rigorous invariance of the transport under rotation by pi/2 about the cubic…
We develop a theory of nonlinear response to an electric field of a two-dimensional electron gas (2DEG) placed in a classically strong magnetic field. The latter leads to a non-linear current-voltage characteristic at a relatively weak…
The conductivity of a two-dimensional electron gas in a parallel magnetic field is calculated. We take into account the magnetic field induced spin-splitting, which changes the density of states, the Fermi momentum and the screening…
The classical two-dimensional problem of non-interacting electrons scattered by short-range impurity centers in the presence of magnetic field is investigated both analytically and numerically. A strong magnetoresistance exists in such a…
A theory of recently discovered anomalous low-field magnetoresistance is developed for the system of two-dimensional electrons scattered by hard disks of radius $a,$ randomly distributed with concentration $n.$ For small magnetic fields the…
An analytical study of the low-field magnetoresistance of a two-dimensional electron gas subject to a weak periodic modulation is presented. We assume small-angle impurity scattering characteristic for high-mobility semiconductor…
The exchange interaction is investigated theoretically for electrons confined to a 2-D sample placed in a linearly varying magnetic field perpendicular to the plane. Unusual and interesting behavior is predicted: starting from zero, as one…
The magnetoresistance of classical two-dimensional electrons scattered by randomly distributed impurities is investigated by numerical simulation. At low magnetic fields, we find for the first time a negative magnetoresistance proportional…
We provide a possible theoretical explanation for the recently observed giant positive magnetoresistance in high mobility low density {\it quasi}-two dimensional electron and hole systems. Our explanation is based on the strong coupling of…
We study the giant magnetoresistance of nanogranular magnets in the presence of an external magnetic field and finite temperature. We show that the magnetization of arrays of nanogranular magnets has hysteretic behaviour at low temperatures…
Magnetic barriers in two-dimensional electron gases are shifted in B space by homogeneous, perpendicular magnetic fields. The magnetoresistance across the barrier shows a characteristic asymmetric dip in the regime where the polarity of the…