AIIIBV Molecular Beam Epitaxial structures and devices for photonics, nanoelectronics, spintronics and quantum computing.

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The roots of the technological revolution which brought about personal computers, fast internet, digital cameras and flat panel displays-to mention just the commodity sector-can be traced directly to the advances in engineering of very thin films of artificial materials. The highest performance electronic devices, such as transistors used in smartphones or satellites, and photonic devices such as semiconductor lasers supporting the ultra-high speed information transfer along the optical fiber networks, are all based on highly perfect crystalline multilayers of semiconductor materials which are deposited using epitaxial processes. Of these devices the Quantum Cascade Lasers (QCLs) represent perhaps the greatest achievement of the epitaxial technology and the greatest triumph of the band theory of solids and band engineering. The active regions of these lasers are typically made of well over a thousand distinct thin layers - quantum wells and barriers - some just a couple of atomic layers thick. Even though the effective thickness of each such quantum barrier can be controlled to within a fraction of an atomic layer, it is the quality of interfaces between the wells and the barriers that limits the device performance. We recently demonstrated the world's record operating temperature of 200K for QCLs working in the very difficult THz spectral region. Increasing their operating temperature to 240K will bring these devices into the mainstream of applications and it is clear that interfacial structure needs to be controlled at atomic scale to achieve this goal. Such control is in fact of paramount importance to many other quantum devices, since as their size shrinks the interfacial regions start to dominate their behaviour. Understanding and controlling the processes of interface formation at atomic scale in Molecular Beam Epitaxy is the key focus of the proposed research program. Insights gained will be used to improve performance of THz QCLs, Quantum Hot Electron Transistors and quantum structures identified as candidates for revolutionary Topological Quantum Computers. The resulting intellectual properties, know-hows and the steady stream of highly qualified personnel will leverage the strong position of the Canadian high-tech industry in the global markets.