Magnetotransport properties of two-dimensional electron gas in AlSb∕InAs quantum well structures designed for device applications

Abstract

The mobility and the sheet electron density of two-dimensional electron gas in AlSb∕InAs quantum well structures optimized for device applications were measured in the temperature range 4.2K<T<90K. A maximum electron mobility μ=3.24×105 was found at 4.2K at a sheet electron density n2D=1.1×1012cm−2. Measurements of the integral quantum Hall and Shubnikov-de Haas oscillations in the temperature range 0.07–9K were also carried out to obtain additional information on the characteristics of the two-dimensional electron gas. The electron effective mass m* and the effective electron g-factor g* were determined from these measurements and found to be, respectively, 0.032m0 and 14.6. The latter is in good agreement with the recent experimental data obtained from cyclotron resonance and titled magnetic-field experiments.

Limiting scattering processes in high-mobility InSb quantum wells grown on GaSb buffer systems

“…5 divided by X(T ) is plotted against the reciprocal magnetic field. The linearity of our calculated data seen in the Dingle plot, is indicative that the Landau level broadening in sample F is field-independent [40] between the onset of the oscillations and the spin splitting, which supports the calculation of the effective g-factor g * previously expounded. The results also portend a valid fit [51] for τ q since the intercept at 1/B = 0 is 4.…”

“…IV.B. We note that this method [40] and the outcome of the calculation crucially depends on the exact determination of the critical fields B c1 and B c2 , which in turn is done by carefully examining the first and second derivatives of R xx (B) versus 1/B as well as the first derivative of the Hall resistance as shown in Fig. 6.…”

Shubnikov-de Haas oscillations of the conductivity of a two-dimensional gas in quantum wells based on germanium and silicon. Determination of the effective mass and g factor

“…Calculations using this relation gave g * The second method for determining g * is based on the assumption that the splitting of the Landau levels engenders a contribution of activation processes, associated with transitions between Landau levels taking account of the spin splitting, to the temperature dependence of the conductivity. 8,9 To describe this contribution with integral values of the filling factor we used the relation xx ͑T͒ = xx c / ͓1 + exp͑⌬ / 2k B T͔͒, where xx c = xx ͑1 / T =0͒. 9 Analysis of the experimental data using this relation makes it possible to determine the energy gap ⌬ = ប c − g * B B for different values of ͑and, therefore, different values of the magnetic field͒.…”

“…8,9 To describe this contribution with integral values of the filling factor we used the relation xx ͑T͒ = xx c / ͓1 + exp͑⌬ / 2k B T͔͒, where xx c = xx ͑1 / T =0͒. 9 Analysis of the experimental data using this relation makes it possible to determine the energy gap ⌬ = ប c − g * B B for different values of ͑and, therefore, different values of the magnetic field͒. Figure 3a displays the experimental curves of xx versus 1 / T on a logarithmic scale for the experimental samples and the fit of the relation presented above to these curves for different values of .…”

Controlling Fermi level pinning in near-surface InAs quantum wells

“…Continual optimization of the growth of InAs quantum well structures has resulted in a steady increase of electron mobility over the years. There have been reports on high mobility InAs two-dimensional electron gases (2DEG) grown on GaAs [20][21][22][23][24][25][26][27], InP [28][29][30][31] and GaSb [32][33][34][35][36]. While InAs and GaSb are nearly lattice matched, the commercial availability and ease of nanofabrication of arsenide-based heterostructures have attracted attention to InP or GaAs substrates.…”