Quantum magnetotransport at a type II broken-gap single heterointerface

We report the study of quantum magnetotransport in a semimetal channel at the type II broken-gap single heterointerface at magnetic field range up to 16 T at low temperature. The GaIn0.16As0.22Sb/InAs heterostructures with high quality abrupt heteroboundary (∼12 Å) were fabricated by liquid phase epitaxy (LPE) on InAs substrates. Electron channel with high carrier mobility (μH=50 000–70 000 cm2/V s) was found at the interface in the isotype p-GaInAsSb/p-InAs heterostructure under low magnetic field up to 5 T. Three series of Shubnikov–de Haas oscillations in Hall conductivity and magnetoresistance were observed under high magnetic fields (9–16 T) at T=1.45 K. Two of them were corresponded to 2D-electron subbands E1 and E2 with carrier concentration n1=4.77×1011 cm−2 and n2=1.82×1011 cm−2, while the significant contribution of the third one corresponding to 2D-hole subband with concentration p∼1012 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 ν=2, 3 and 6 when ultraquantum limit for E1 subband was realized. It is the first demonstration of QHE in a type II single GaInAsSb/InAs heterostructure with self-consistent quantum wells grown by LPE.