Magneto-transport of InAs-quantum wells using InP0.69Sb0.31as a barrier material

InAs/InP_0.69Sb_0.31quantum-well structures grown by metal organic vapor-phase epitaxy are studied by temperature-dependent Hall measurements and by quantum Hall and Shubnikov de Haas effect measurements. At temperatures below 0.3 K a two-dimensional electron gas without a conductive by-pass was demonstrated. For a two-dimensional electron gas with a sheet electron concentration of 2.2 × 10¹²cm⁻²mobilities as high as 118 000 cm²(Vs)⁻¹were observed. In contrast to samples doped on both sides of the quantum well, a beating pattern in the longitudinal resistance was observed for samples which were doped on only one side. This effect is explained by spin–orbit coupling of the electrons in the quantum well which leads to a separation in two spin-splitted subbands. A spin-split energy in the range from 6.9 meV to 8.4 meV was extracted from the Shubnikov de Haas measurements.