Beckman Fellow 2013-14

Matthew Gilbert

Electrical & Computer Engineering

Gilbert imageTransformative Information Processing in 3D Heterogeneously Integrated Topological Networks

Our society increasingly depends on systems that process digital information. Most of the processing currently is accomplished using Complementary Metal Oxide Semiconductor, an architecture based on a very simple semiconductor device in which an applied electric field controls the flow of current (on, off) between two electrical contacts. Continued miniaturization of this device is predicted to result in diminishing performance returns and increasing demand for power. It has become a national challenge to find alternate materials and device technologies that can replace the current architecture.

Topological insulators (TI), a new class of materials, hold significant potential for replacement device technologies. To date, the most technologically relevant TI is Bi2Se3, which has been predicted to be a topological insulator at room temperature, have a large energy gap of 0.35 eV3, and have protected surface states on each face of the 3D crystal. The challenge is to induce technologically relevant behavior in Bi2Se3 (e.g., create transistors, switches, memory) in a way that allows devices to be coupled and scaled to large numbers. Such novel and tunable electrical-transport properties potentially could be induced by separating the surfaces spatially, then coupling them to each other and to other materials. In fact, this is the most likely route through which TIs can make a technological impact.

During his Center appointment, Professor Gilbert will explore the use of correlated surface states and interactions between dissimilar materials such as Bi2Se3, in order to form a cohesive 3D integrated network device. His group will pair TI thin-films with dissimilar materials to induce different topological phases, then stack the layers laterally and vertically in various combinations to create 3D networks. They will also conduct multi-scale simulations to explore network and system designs and determine their overall performance; and explore new topological states to find more efficient base materials.

The research is expected to break new ground in the understanding of these hybrid devices. Integrating the devices into a 3D network would truly revolutionize information-processing technology.