The Quantum Semiconductor Systems Group focuses on the quantum-mechanical properties of electrons in ultra-high purity III-V semiconductor devices and is affiliated with the Department of Physics and Astronomy, School of Materials Engineering, the School of Electrical and Computer Engineering and Birck Nanotechnology Center at Purdue University. We are the home of Station Q Purdue, signifying our strong collaboration with Microsoft Station Q to develop systems for topological quantum computing.
To build nanostructures needed for our experiments, we devote significant resources to a high-purity growth technique known as molecular beam epitaxy (MBE). MBE allows us to build semiconductor structures one atomic layer at a time and thus engineer the electronic energy levels to suit our needs. As practiced in our group, MBE allows for exploration of correlated electron motion in materials with very low residual disorder. We can build a two-dimensional electron gas (2DEG) in which the mean free path exceeds 0.35mm at low temperatures!
We study quantum transport in our low temperature laboratory where we can cool 2DEGs to T=10mK at high magnetic fields. Ongoing projects include study of exotic topological phases in the fractional quantum Hall regime, development and study of novel semiconductor/superconductor hybrid structures to host Majorana fermions, and development of devices for spin-based quantum bits (qubits). Much of our effort is presently directed towards semiconductor-based quantum computing; we are fortunate to collaborate with many of the leading groups around the world in this exciting field.
In a parallel effort some of our team works on development of novel light sources in III-Nitride materials. This research relies on innovative approaches to material growth and is done in close collaboration with the Malis Group at Purdue.