Negative transverse magnetoresistance of the two-dimensional electron gas in quantum well with parabolic confinement potential under an in-plane magnetic field Abstract. We developed a quantitative theory of transverse magnetoresistance for the twodimensional electron gas (2DEG) in a quantum well with parabolic confinement potential in the magnetic field in the plane of the free movement of electrons. Our theory is based on the solution of Boltzmann kinetic equation for the components of the tensors of kinetic coefficients, when the perturbing force is directed along the plane of the free movement of electrons, and Titeike's formula for the diagonal component of the conductivity along the direction of confinement, based on the idea of the drift of the centres of cyclotron orbits in the crossed electric and magnetic fields. Numerical calculations have been performed for the 2D electron gas in GaAs/Al x Ga 1-x As QWs. It is shown, that the magnetoresistance is negative and equal about 50% in the weak magnetic field case, ω c <<ω 0 if the quantum limit 0 0 k T ω > is fulfilled.
IntroductionMuch interest has been aroused recently in the behavior of two-dimensional electron systems in the presence of magnetic field parallel to the 2DEG layer. The electrical characteristics of these systems are of interest both for fundamental and applied physics. The study of magnetotransport in these structures makes it possible to understand better the mechanisms and parameters of electron scattering. The theory of the quantum galvanomagnetic effects in size-quantized systems was studied in [1][2][3][4]. In [1,2] the case of a strongly degenerate electronic gas was considered with the focus was on oscillation phenomena. In [3] the conductivity in QW structures has been calculated, and the size dependence of conductivity in the quantum limit for different mechanisms of electronic scattering has been considered. The authors used the kinetic equation method and the density matrix approach. In the latter case, the scattering was entered into the equation of motion for the density matrix through the lifetime of a quantum state. In [5] the magnetoresistance was studied for the case of electron scattering on a deformation potential of a three-dimensional crystal in a transverse magnetic field. It has been shown that for semiconductors with low mobility the magnetoresistance is negative in weak transverse magnetic fields. In the same paper it was noted that the negative magnetoresistance is not directly associated with weak localization.