Very shallow two-dimensional electron gas realized by In{sub}xAl{sub}(1-x)As/InAs single quantum well grown on GaAs (111)A substrate

摘要

Recently, transport properties of quantum dots (QDs), fabricated mainly in Si or GaAs based material, have been extensively studied. InAs is unique material with a large g-factor and a small effective electron mass, and dose not have a surface depletion effect. Until now, two-dimensional electron gas (2DEG) has been realized in AlGaSb/InAs [1] and GaAs/InAs on GaAs (111)A [2] systems. However, the formation of high quality lateral QDs in these system is, in general, not easy with surface metallic gates, because of the poor gate quality in the former and the Fermi level pinning at the highly mismatched interface (GaAs/InAs) in the latter. In this study, we report on the MBE growth of the shallow InAs 2DEG quantum-well structures on GaAs (111 )A substrates with InAlAs spacer layers which we expect to overcome the interface problem.