Research @ Waterloo – Dr. Wilhelm and the Quantum Device Theory group

Moe Adham - 4A Mechatronics
Posted on: February 3, 2010

If you have been on campus for more than four months, you have hopefully heard the words “Institute of Quantum Computing” (IQC). While a recent Bond film may have you confused, I can assure you that quantum computing has little to do with securing the water supply of a South American country. I sat down with Dr. Frank Wilhelm, head of the Quantum Device Theory (QDT) group to get a better idea of what actually goes on at the institute. The work being done here is really quite exciting and has some far reaching goals. Unfortunately for this columnist, it isn’t exactly the easiest topic to understand, let alone cover in five hundred words.

The Quantum Device Theory group is a research group in the department of physics and astronomy, with Dr. Frank Wilhelm cross-appointed to the ECE department. The group members are mostly post-docs and grad students in applied theoretical physics. Their research goals are simple to summarize: the design of devices that can be used in quantum computers. Quantum computing was originally a purely theoretical and mathematical idea. The question used to be: if we can harness quantum physics to build a computing device, would it be better than a classical computer? It turns out the answer is yes. Now, a more difficult question is posed: How do you build such a computer?

First realizations of quantum computing were around 15 years ago in atomic physics, quantum optics, and nuclear resonance. Scaling these original realizations was not possible and to truly harness the power of quantum computing you need to scale, preferably to the same level as an integrated circuit.  The worldwide record at the moment is a 14 Qubit (Quantum Bit) device. This feat has already been achieved at the IQC, using nuclear magnetic resonance (NMR) in a liquid. The goal is to someday move towards using electronic elements, similar to an integrated circuit. To achieve this, one has to go back to the drawing board and do the fundamental research that can change the world.

The group is currently focusing on superconducting devices. While this requires cooling to very low temperatures, it is not a real concern. Initial customers of these quantum systems will more than likely be supercomputing operators. Some quantum devices do exist today, but the market remains in its infancy. Currently, the recognized biggest achievement is running on a 2 Qubit system. In the next decade, you probably won’t be using a quantum device in consumer electronics. The industry is still in pre-prototype and developing concepts. The most obvious applications are database search, as well as breaking cryptographic codes. You really wouldn’t want a quantum computer on your desk, since these systems excel at massive parallelization. Would you really want to type an entire essay at once, and then have it all appear at the same time?

The group has recently received funding from the Intelligence Advanced Research Projects Activity (IARPA). This funding is aimed at a collaborative effort between materials science and physics. When it comes to quantum computing, materials have to be close to perfect and levels of imperfections that may be permissible in Integrated Circuits can have very adverse effects on quantum devices. The group is interested in semiconductor based realizations based on gallium arsenide using quantum dots. For engineering students interested in Quantum Computing, there are a number of avenues to proceed. Material science and engineering will become much more involved as new methods are needed to actually build these devices. There are opportunities for engineering students interested in participating as USRA or as a co-op summer placement. Students interested in device design should focus on devices courses, be open to new paradigms, and have strong knowledge of quantum mechanics. There is also a fourth year course being offered soon through the department of physics in quantum device applications. If you are interested in the QDT group, feel free to check out their website at