Research within the Narayanamurti Group is directed at the physics of hot electron- and hole- transport in novel semiconductor electronic materials and devices. A key goal is to study quantum confinement effects in nanostructures. The group interacts with similar electronic materials efforts at other universities, government, and industrial research laboratories. Our collaborators include:

• R.D. Dupuis, Georgia Institute of Technology
• Arthur Gossard, Steven DenBaars, James Speck, University of California, Santa Barbara
• C.W.Tu, University of California, San Diego
• Angelo Mascarenhas and Y. Zhang, National Renewable Energy Laboratory
• Nitin Samarth, Pennsylvania State University
• Piedong Yang and Arun Majumdar, University of California, Berkeley

The primary experimental methods currently employed within the Narayanamurti Group are Scanning Tunneling Microscopy (STM) and Ballistic Electron Emission Microscopy (BEEM). Unlike more traditional methods, the STM based BEEM technique allows the study of local transport with nanometer resolution. Depending on the carrier mean free path, interfaces buried deep within the semiconductor can be probed. In addition, the energy distribution of the injected carriers can be independently varied by simply varying the tip-metal voltage. At present, there are several operational BEEM/STM set-ups for carrying out such experiments. Of these, one allows variable temperature operation between 77 K and 300 K in a residual exchange gas environment while another UHV system allows similar capability under Ultra High Vacuum (UHV) conditions. A recently purchased, commercially built cryogenic Scanning Tunneling Microscope has extended the capability into the pumped liquid Helium temperature range ( > 1.1 K).