Quantum magnetotransport at a type II broken-gap single heterointerface

We report the study of quantum magnetotransport in a semimetal channel at t he type II broken-gap single heterointerface at magnetic field range up to 16 T at low temperature. The GaIn0.16As0.22Sb/InAs heterostructures with hi gh quality abrupt heteroboundary (similar to 12 Angstrom) were fabricated b y liquid phase epitaxy (LPE) on InAs substrates. Electron channel with high carrier mobility (mu (H) = 50000-70000 cm(2)/V s) was found at the interfa ce in the isotype p-GaInAsSb/ p-InAs heterostructure under low magnetic fie ld up to 5 T. Three series of Shubnikov-de Haas oscillations in Hall conduc tivity and magneto resistance were observed under high magnetic fields (9-1 6 T) at T = 1.45 K. Two of them were corresponded to 2D-electron subbands E -1 and E-2 with carrier concentration n(1) = 4.77 x 10(11) cm(-2) and n(2) = 1.82 x 10(11) cm(-2), while the significant contribution of the third one corresponding to 2D-hole subband with concentration p similar to 10(12) = cm(-2) has been pronounced in the range 13-16 T. The most impressed result is the observation of the integer quantum Hall effect (QHE) plateaus in the Hall conductivity with the filling factor v = 2, 3 and 6 when ultraquantum limit for E-1 subband was realized. It is the first demonstration of QHE i n a type II single GaInAsSb/InAs heterostructure with self-consistent quant um wells grown by LPE. (C) 2001 Elsevier Science B.V. All rights reserved.