Exploiting Noisy Quantum Electrons
Mesoscopic physics is an emerging field of physics on the threshold between the microscopic and macroscopic world. It involves the study of electronic systems that are much larger than the size of a typical atom, but are nonetheless strongly influenced by non-intuitive, non-classical quantum mechanical effects. Such quantum effects are usually associated with the odd behaviour of particles on the atomic or sub-atomic length scale; part of the appeal (and complexity) of mesoscopic systems is that these effects now appear on a much larger length scale. Furthermore there is challenging interplay between these quantum effects, the presence of disorder, and interactions between particles. Examples of mesoscopic systems include carbon nanotubes and micron-sized superconducting metallic grains. Knowledge of the mesoscopic regime is increasingly important as current microelectronic technology pushes towards smaller and smaller devices.
Recently, researchers have been trying to directly exploit the quantum nature of mesoscopic systems for information processing, as in creating a solid-state quantum computer. A crucial challenge in these endeavours involves understanding and controlling mesoscopic electron noise. Such noise affects one's ability to read out information from these systems, and can completely suppress their quantum behaviour. The study of noise is also important as it can reveal fundamental effects at the mesoscopic scale not accessible by other means.
Dr. Aashish Clerk's research has already addressed several significant theoretical questions about noise in the mesoscopic regime, many of which are directly relevant to quantum information processing. He has been especially interested in understanding the noise properties of mesoscopic systems when used as detectors (e.g., a read-out device for a quantum computer), and in clarifying the connection between noise and the information that emerges from these systems. As a Canada Research Chair, he is extending this work to a broader class of systems, including those where strong inter-particle interactions are vital.