Research interests: molecular beam epitaxy; quantum-dot and quantum-well photonic devices
Professor Zbig Wasilewski is professor in the Electrical and Computer Engineering Department, cross-appointed to the Department of Physics and Astronomy at the University of Waterloo. Wasilewski also holds a University of Waterloo Endowed Chair in Nanotechnology and an Associate Faculty position at the Institute for Quantum Computing. He is internationally renowned for his contributions to the field of Molecular Beam Epitaxy (MBE), quantum-dot and quantum-well photonic devices, as well as quantum structures and devices based on high mobility 2D electron gases, such as lateral few-electron quantum dot circuits – potential building blocks of quantum computers.
Wasilewski’s research interests include MBE and nanofabrication of III-V semiconductor structures for quantum optics, photonics, nanoelectronics and quantum computing applications. The MBE laboratory, led by Wasilewski, has demonstrated THz Quantum Cascade Lasers with the world’s highest operating temperatures. These devices are among the most complex man-made quantum structures, comprising close to 2000 quantum wells and barriers, with thicknesses controlled to a fraction of atomic layer. Recently his research has expanded to the growth of ultra-high purity, single crystal aluminum layers for superconducting resonators with applications in quantum computing and plasmonics.
Wasilewski received his MSc degree in Physics from the University of Warsaw, Poland, and subsequently joined the Semiconductor Physics Research Group at the Institute of High Pressure Physics, where he worked until 1986. During that period he focused primarily on low-temperature magneto-optical studies of semiconductors under high hydrostatic pressures (up to 25,000 atmospheres). Much of this research he conducted in the Professor R.A. Stradling Laboratories in the Physics Department, University of St. Andrews, Scotland. He earned his doctoral degree from the Institute of Physics of the Polish Academy of Sciences in 1986. In 1988, after a post-doctoral appointment at the Imperial College, London, where he expanded his work to other material systems and nanostructures, he joined the National Research Council of Canada (NRC), shifting his research focus to molecular beam epitaxial growth and characterization of quantum structures and devices based on III–V semiconductor compounds. In 2006, Wasilewski was promoted to Principal Research Officer – NRC’s top research rank. In July 2012, Wasilewski joined the University of Waterloo as a full Professor and a University of Waterloo Endowed Chair in Nanotechnology.
Wasilewski is a co-author of more than 450 refereed journal and conference proceedings articles (over 11,000 citations to his work with an h-index of 51 and i10‑index of 188 – Google Scholar, 2016). In 2012, Wasilewski was awarded the title of Professor of Physics by the President of Poland, in recognition of his exceptional track record in research and his role in developing the field of GaN-based optoelectronics in Poland.
PhD, Semiconductor Physics, Institute of Physics, Polish Academy of Sciences
MSc, Semiconductor Physics, University of Warsaw, Poland
Molecular Beam Epitaxy (MBE) and nanofabrication of III-V semiconductor structures for quantum optics, nano-photonics, nano-electronics and quantum computing applications:
- Arsenides and Antimonides – (Al, Ga, In)(As, Sb).
- Nitrides - (Al, Ga, In)N
Multi-quantum-well structures for novel light sources and sensors
Photonic infrared and terahertz emitters are well positioned for demonstrating high impact results on a relatively short timescale. Indeed, MBE laboratory led by Dr. Wasilewski recently demonstrated world’s highest operating temperatures for GaAs/AlGaAs-based THz Quantum Cascade Lasers. These devices are among the most complex man-made quantum structures. Research in this field focuses on their further optimization as well as on development of complementary detector structures and focal-plane arrays. In parallel (In, Ga, Al)(Sb, As) superlattices and multi-quantum well structures are developed for broad range of applications involving photon emission and detection in midinfrared as well as THz spectral regions.
Quantum Dot systems for quantum computing and solar energy applications
MBE-grown InAs/GaAs quantum dots (QDs) systems have proven to be one of the most versatile “playgrounds” in spintronics. Indeed, the electron spin in singly charged InAs QDs can serve as a qubit for all-optical solid state quantum computing. Advanced spin manipulation and readout has already been demonstrated in QD molecules. The best technique for creating and fine-tuning such pseudo-molecular systems is the so called In-flush method originally developed in Professor Wasilewski’s MBE laboratory. In fact, very recently optical control of the entangled state of two electron spins in such an InAs double-dot system has been used to demonstrate two-qubit gates with an interaction rate as high as 30 GHz while interactions rates approaching 1 THz should be possible in the future. One of the most fascinating research directions here is scaling of such ensembles by increasing the number of interacting quantum dots and/or coherent coupling of such pseudo-molecular clusters using photonic crystals. Quantum computing and quantum cryptography do not exhaust the potential of MBE-grown InAs quantum dots. It is expected that such nanostructures will lead to development of novel enhanced efficiency photovoltaic devices relying on so-called intermediate band absorption. Also development of GaSb and InSb dots in GaAs matrices, due to type-II band offsets for such material combinations, is predicted to enhance charge separation, and thus decrease random recombination in such systems, again making them potentially advantageous for solar cell applications.
Novel 6.1Å materials for nano-electronics, spintronics and emerging technologies.
The 6.1Å material system encompasses semiconductor compounds lattice-matched to either InAs or GaSb substrates. Very high energy barriers, very low electron effective mass and large spin-orbit interactions for these materials provide a unique foundation for a wide range of novel photonic and electronic devices. Some of the examples are: (i) ultra-fast, ultra-low power nano-electronics (ii) spintronic concept devices and (iii) fundamental and applied research in the emerging field of topological Insulators.