Magnetotransport in high-g-factor low-density two-dimensional electron systems confined inIn0.75Ga0.25

Abstract

Magneto-transport in high g-factor, low-density two-dimensional electron systems confined in In We report magneto-transport measurements on high-mobility two-dimensional electron systems (2DESs) confined in In0.75Ga0.25As/In0.75Al0.25As single quantum wells. Several quantum Hall states are observed in a wide range of temperatures and electron densities, the latter controlled by a gate voltage down to values of 1 × 10 11 cm −2 . A tilted-field configuration is used to induce Landau level crossings and magnetic transitions between quantum Hall states with different spin polarizations. A large filling factor dependent effective electronic g-factor is determined by the coincidence method and cyclotron resonance measurements. From these measurements the change in exchange-correlation energy at the magnetic transition is deduced. These results demonstrate the impact of many-body effects in tilted-field magneto-transport of high-mobility 2DESs confined in In0.75Ga0.25As/In0.75Al0.25As quantum wells. The large tunability of electron density and effective g-factor, in addition, make this material system a promising candidate for the observation of a large variety of spin-related phenomena.

Scattering mechanisms in undoped In0.75Ga0.25As/In0.75Al0.25As two-dimensional electron gases

“…The combination of high m and relatively low n is a crucial requirement to study different transport properties when few Landau levels are filled at experimentally accessible magnetic fields [7]. To improve the transport properties of such structures, it is important to understand the scattering mechanisms limiting the low-temperature electron mobility.…”

Giant enhanced g-factors in an InSb two-dimensional gas

“…Previous investigations of Zeeman splitting in narrowergap semiconductors have usually led to indications of g-factor enhancement [14][15][16][17][18] although some authors suggest that the effect is small. 19 To date however no systematic studies comparable to the work performed in GaAs and silicon have been reported.…”

A ballistic two-dimensional-electron-gas Andreev interferometer

“…In the last few years, the major efforts have been put on InAs and InAs/AlSb 2DEG-based hybrid structures. These materials exhibit a larger g-factor and spin-orbit coupling in comparison to those existing in In 0.75 Ga 0.25 As semiconductor alloys [13][14][15][16] , being therefore more attractive for the implementation of a topological non-trivial phase 1-3 . Moreover, the interplay between spin-orbit coupling and spin-splitting (due to the application of an external magnetic field) may lead to an advanced manipulation and control of the triplet superconducting correlations 17,18 with potential application in spintronics.…”