Large magnetoresistance of a dilutep-Si/SiGe/Siquantum well in a parallel magnetic field

Abstract

We report the results of an experimental study of the magnetoresistance ρxx in two samples of p-Si/SiGe/Si with low carrier concentrations p=8.2×10 10 cm −2 and p=2×10 11 cm −2 . The research was performed in the temperature range of 0.3-2 K in the magnetic fields of up to 18 T, parallel to the two-dimensional (2D) channel plane at two orientations of the in-plane magnetic field B against the current I: B ⊥ I and B I. In the sample with the lowest density in the magnetic field range of 0-7.2 T the temperature dependence of ρxx demonstrates the metallic characteristics (dρxx/dT >0). However, at B =7.2 T the derivative dρxx/dT reverses the sign. Moreover, the resistance depends on the current orientation with respect to the in-plane magnetic field. At B ∼ = 13 T there is a transition from the dependence ln(∆ρxx/ρ0) ∝ B 2 to the dependence ln(∆ρxx/ρ0) ∝ B . The observed effects can be explained by the influence of the in-plane magnetic field on the orbital motion of the charge carriers in the quasi-2D system.

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

“…With this dependence, we can analyze the possible cause of the anomalies in conductivity that appear at a filling factor ν = 2 in a pSi/SiGe/Si sample with p = 2 × 10 11 cm −2 . The asymmetric quantum well in this sample was 30 nm wide, and the sample structure was described in [9].…”

Effects of spin polarization in the HgTe quantum well

“…7 with MR in a pure B || and seen is that just the field of a full spin polarization separates two kinds of dependences in ρ xx (B = B || ): a somewhat complicated function at lower fields, where two spin subbands are filled, from a monotonously increasing one, for a single subband filled, at higher fields as has been observed in a number of studies. 7,8,15,16 …”

Magnetoresistance in dilute p-Si/SiGe in parallel and tilted magnetic fields

“…The research was performed in the temperature range of 0.3-2 K in the magnetic fields of up to 18 T, parallel to the two-dimensional (2D) channel plane [6] at two orientations of the in-plane magnetic field B against the current I: B ⊥ I and B I. In the sample with the lowest density in the magnetic field range of 0-7.2 T the temperature dependence of ρ xx demonstrates the metallic characteristics (dρ xx /dT >0).…”