Prospects of advanced quantum nano-structures and roles of molecular beam epitaxy

Over the last three decades, layered nano-structures, such as superlattices (SLs) and quantum wells (QWs) have played notable roles in expanding the forefront of physics and electronics. The births and advances of QW lasers, selectively-doped heterojunction FETs (HEMTs), and related 2D electron devices, for example, have made huge impacts in various branches of information technology. One should note that all of these nano-structures were first realized by molecular beam epitaxy (MBE) that permitted the formation of atomically flat and abrupt hetero-interfaces. This marvellous success of MBE has then inspired related attempts in other research areas, inducing breakthroughs in such fields as magnetic and superconducting materials and devices.