We report magnetotransport measurements of a gated InSb quantum well (QW) with high quality Al2O3 dielectrics (40 nm thick) grown by atomic layer deposition. The magnetoresistance data demonstrate a parallel conduction channel in the sample at zero gate voltage (Vg). A good interface between Al2O3 and the top InSb layer ensures that the parallel channel is depleted at negative Vg and the density of two-dimensional electrons in the QW is tuned by Vg with a large ratio of 6.5 × 1014 m-2 V-1 but saturates at large negative Vg. These findings are closely related to layer structures of the QW as suggested by self-consistent Schrödinger-Poisson simulation and two-carrier model.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)