Quantum transport and its manipulation in semiconductor quantum devices

Abstract

Recently, progress in nanotechnology and development of new material have enabled us to observe and control not only quantum phenomena but also relativistic quantum phenomena, both of which manifest themselves in nanostructured semiconductors. Consequently, exotic physics is being discovered day by day and quantum devices with new functionalities are being realized all over the world. In this paper, we report relativistic quantum phenomena observed in semiconductor nanodevices, including epitaxial graphene grown on silicon carbide and III-V semiconductor nanowire FETs. For epitaxial graphene, we report on experiments on quantum Hall effect and quantum capacitances, which reflect the Dirac cone band structure of graphene. For III-V semiconductor nanowires, we demonstrate highly efficient electric-field control of spin-orbit interaction, which appears as a consequence of the relativistic quantum effect.