Mike’s research group focuses on the growth of narrow-gap semiconductors and device applications for these materials. His group uses molecular beam epitaxy to grow heterostructures for three research efforts: high-mobility and spin-dependent electron transport experiments, mid-infrared interband-cascade devices, and nanostructures for photovoltaic applications. Because the bandgap of InSb is the smallest of all binary III-V compounds, two-dimensional electron systems in InSb quantum wells have a small effective mass, a large g-factor, and strong spin-orbit effects. The room-temperature mobility in these structures is higher than in quantum wells made of any other semiconductor. The group is exploring ways to exploit this and other features in devices based on ballistic transport and electron spin. The group also searches for new quantum materials that exhibit topological-insulator behavior.