Possible sign reversal of the Rashba coefficient in InAs-based heterostructures

We have examined InAs-based heterostructure whose Rashba effect is made anomalously large by band-gap engineering. Shubnikov-de Haas oscillation and weak antilocalization (WAL) were measured under positive and negative gate voltages, respectively, to examine the gate modulation of Rashba effect in the InAs-based heterostructure. Suppression of WL in positive and slightly negative gate voltage region (V-g > -0.3 V) is presumably caused by the increased Rashba effect due to band discontinuity under the peak position of wavefunction. WL appearance in the middle range of gate voltage bias was explained consistently with the decreased SO effect in the gate voltage region where sign change of Rashba factor takes place. (C) 2009 Elsevier B.V. All rights reserved.