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We have investigated spin-related oscillatory magnetoresistances of the two-dimensional electron gas in the inversion layer on bulk p-Hg1-xCdxTe at low temperatures. The oscillatory magnetoresistances are found to display beating pattern at low magnetic fields and to exhibit spin-splitting structure at high magnetic fields. We attribute the beating pattern to zero-field spin splitting due to spin-orbit coupling by analyzing fast-Fourier-transform results and Hall resistance. By modulating the oscillatory magnetoresistances we investigate the influence of spin-orbit coupling, Zeeman splitting, and the second populated subband on the appearance of beating patterns and the spin-splitting structure in oscillatory magnetoresistances. The strong spin-orbit coupling and the large effective g factor are demonstrated to be the significant parameters in controlling the appearance of spin-related oscillatory magnetoresistance in the inversion layer on bulk p-Hg1-xCdxTe. A good agreement between magnetoresistance data and theory suggests a spin-orbit coupling parameter α = 2.8 × 10-11 eV•m and the effective g factor g* = -44.0. The spin-orbit coupling effect presented in the inversion layer on bulk p-Hg1-xCdxTe provides a potential candidate for spintronic devices. [ABSTRACT FROM AUTHOR]

We study the insulator-quantum Hall conductor transition in two high-density gated InGaAs/InAlAs quantum well samples. We observe a well-defined critical magnetic field and verify this marks a genuine phase transition by investigating the scaling behavior of the longitudinal resistivity with field and temperature at fixed electron density. Consistent with prevailing experimental results the critical field decreases with increasing electron density in one sample (QW0710). In the other sample (QW0715), with higher delta doping density, however, we unexpectedly find that the critical field increases with increasing electron density. This unexpected behavior may be the result of the system entering the classical percolation regime. [ABSTRACT FROM AUTHOR]

The weak antilocalization (WAL) effects of the two-dimensional electron gas (2DEG) in high mobility AlxGa1-xN/GaN heterostructure as well as beating patterns in the Shubnikov–de Haas (SdH) oscillatory magnetoresistance have been investigated by means of magnetotransport measurements before and after illumination. The zero-field spin splitting mainly arising from the Rashba spin-orbit coupling effect is studied using the weak antilocalization and beating patterns analysis, respectively. The Rashba spin-orbit coupling constant α deduced using the weak antilocalization analysis showed a good agreement with that estimated from the analysis of the beating patterns for the sample before and after illumination. For our sample, the electron motion in the high mobility system is in the ballistic regime, the experimental WAL curves were fitted by a simulated quantum conductance correction according to a model proposed by [Golub [Phys. Rev. B 71, 235310 (2005)]. [ABSTRACT FROM AUTHOR]

The oscillatory magnetoresistance of the two-dimensional electron gas (2DEG) in AlxGa1-xN/GaN heterostructures has been studied by means of magnetotransport measurements at low temperatures and high magnetic fields. The split peaks of the Shubnikov–de Haas oscillations are observed at high magnetic fields, which are attributed to the spin splitting of the 2DEG. It is found that the spin splitting energy becomes smaller with an increase in magnetic field, indicating that the Zeeman spin splitting is not dominant at measured magnetic field range. Within this magnetic field range, the zero-field spin splitting, as well as Zeeman spin splitting, affects the split peaks in the oscillatory magnetoresistance of the 2DEG in AlxGa1-xN/GaN heterostructures. [ABSTRACT FROM AUTHOR]

The magneotransport properties of a high carrier concentration and high mobility 20-nm thick In0.53Ga0.47As/In0.52Al0.48As quantum well (QW) are investigated by tilt angle dependent Shubnikov-de Haas oscillations and by weak antilocalization (WAL) in an in-plane magnetic field. The effective g-factor g* and zero field spin splitting Δ0 are extracted from tilt angle dependent beating pattern. We found that g* shows a dramatic reduction with increasing carrier density due to the increased effective band gap. Furthermore, an anomalously rapid suppression of the WAL effect with increasing in-plane magnetic field B|| is observed. This reveals that the total dephasing rate is not solely contributed by Zeeman splitting. The microroughness scattering in the QW is proposed to be another factor to cause the dephasing and thus responsible for this effect. [ABSTRACT FROM AUTHOR]