TUNABLE ELECTRON-HOLE GASES IN GATED INAS GASB/ALSB SYSTEMS/

Gated structures have been fabricated on the InAs/AlSb/GaSb system ena bling the control of the relative electron and hole carrier-densities in these type II crossed band gap structures. By using insulated gates , a wide gate voltage range, with very low leakage levels, is obtained , allowing the study of these systems from electron dominated transpor t through to hole dominated. Associated with this transition, a change from positive to negative transconductance is observed. Studies of th e quantum Hall effect show features related to both electron and hole Landau level formation with the crossover from electron to hole domina ted transport found to be a function of the perpendicular magnetic fie ld. (C) 1997 American Institute of Physics.