Magnetoresistivity and acoustoelectronic effects in a tilted magnetic field in p-Si/SiGe/Si structures with an anisotropic g factor

Abstract

Magnetoresistivity ρxx and ρxy and the acoustoelectronic effects are measured in p-Si/SiGe/Si with an impurity concentration p = 1.99 × 10 11 cm −2 in the temperature range 0.3-2.0 K and an tilted magnetic field up to 18 T. The dependence of the effective gfactor on the angle of magnetic field tilt θ to the normal to the plane of a two dimensional p Si/SiGe/Si channel is determined. A first order ferromagnet-paramagnet phase transition is observed in the magnetic fields corresponding to a filling factor ν = 2 at θ ≈ 59 o -60 o .

Absorption of electromagnetic radiation in a quantum wire with an anisotropic parabolic potential in a transverse magnetic field

“…Here, x 0 = , z 0 = , ω z = , ω x = eB x /m*c, and the angle α is expressed in terms of the angle of inclination of the magnetic field to the wire axis θ (sinθ = B x /B) by the formula The energy spectrum is (3) where the hybrid frequencies are and and M is defined by the formula We assume that the polarization vector is directed along the axis x. Then the operator of the electronphonon interaction is (4) where N f is the number of photons, e is the real part of the permittivity, and V is the normalization volume.…”

“…In the last few years, the photoresponse of twodimensional (2D) and quasi-2D systems in a magnetic field attracts growing attention [1][2][3][4][5][6]. This is due to the important fact that, by studying the photoresponse, it is possible to gain information on the spectrum of charge carriers in the sample, specifically, on the dependence of the spectrum on the magnetic-field strength and direction [7].…”

“…It should be noted that, as follows from publications [3,7,8], the use of magnetic fields inclined to the symmetry axis of the system provides additional possibilities for studying the parameters of the spectrum of charge carriers and the features of scattering. In [9], the effect of spin-orbit interaction on the absorption of electromagnetic radiation in a quantum wire was studied.…”

Magnetoresistivity in a tilted magnetic field in p-Si/SiGe/Si heterostructures with an anisotropic g-factor. Part II

“…[4] A third set of p-Si/SiGe/Si systems have such anomaly in ρ xx at ν = 3/2, but it does not depend on the tilt angle. [3] In our earlier article [7], we analyzed the conductivity at ν=2 in tilted magnetic fields in a sample with p=2×10 11 cm −2 and demonstrated the presence of a ferromagnetic-paramagnetic (F-P) transition at a tilt angle of about 60 o . It should be noted that at ν=3/2 we did not observe any significant variation of the conductivity, instead a resistivity peak of the re-entrant-transitiontype occurred in this region of filling factor.…”

Magnetic response of a quantum wire of elliptical cross-section in a magnetic field perpendicular to the axis of the wire

“…Effects arising in the magnetic field perpendicular to the axis of the wire in electronic systems are due to the fact that the motion in the plane of confinement and perpendicular to it is connected by a magnetic field whose direction is determined by the angle θ, B = B(sin θ, cos θ) [1][2][3][4]. The effect of the spin-orbit interaction on the magnetization of low-dimensional systems has been investigated [5][6][7][8][9][10][11][12][13].The energy spectrum of electrons in low-dimensional systems has been studied in [14].…”