Nanometer-scale quantum channels defined by reactive ion etching in InAs/AlSb heterojunctions

An approach to the lateral confinement of electrons in an InAs quantum well has been developed. Conducting quantum wires, rings, and dots with lateral dimension greater than or equal to 50 nm have been fabricated by using electron-beam lithography and reactive ion etching. Due to the Fermi level pinning at InAs surface, the lateral confinement is abrupt and approximately square. Magnetotransport characterization on a series of fabricated hallbars demonstrate that, despite damage by energetic ions, the electron transport in these quantum wires is in the quasiballistic regime at 4.2 K. (C) 2000 American Institute of Physics. [S0003-6951(00)02044-1].