Nanoelectronics, Plasmas, and Accelerator Technology

Peng Zhang | |


The Nanoelectronics, Plasmas, & Accelerator Technology (NanoPATh) Laboratory is broadly interested in theoretical and computational research in nanoelectronics, electromagnetic fields and waves, plasmas, and accelerator technology. We identify the practical problems and explore the underlying physics for the development of novel nanoscale devices, emerging plasma and vacuum nanoelectronics, compact radiation sources (radio frequency - microwave - millimeter wave - THz - x-ray), and compact accelerators.

Currently, we are working on the theory and modeling of the highly nonlinear electron emission from a metal surface illuminated by a laser. Electron sources are important to applications such as microwave generation, space-vehicle neutralization, X-ray generation, e-beam lithography, and electron microscopy. We study ultrafast strong field photoemission from DC biased metal surfaces, by solving the time-dependent Schrödinger equation. Various electron emission mechanisms, including multiphoton emission, optical or dc field emission, single-photon induced over-barrier emission, and various combinations of them, are all handled in our single formulation. The ultrashort electron bunches produced would enable many exciting technological developments, such as ultrafast electron diffraction and four-dimensional (4D) time-resolved electron microscopy.

Current research projects also include contact resistance and quantum tunneling, and electron beam interaction with novel structures. We are exploring the scalings of contact resistance and of nanoscale charge transport across interfaces. This study aims to minimize contact resistance, which is one of the major limiting factors to devices made of exceptional materials, such as carbon nanotubes (CNTs), graphene, and diamond. We are also modeling the Smith-Purcell (SP) radiation, which is generated from electrons propagating close to the surface of metallic periodic gratings. Because of its high tunability and high power, SP effect is attractive to the development of compact light sources, with applications in high-resolution imaging, noninvasive sensing, high-data rate communications and material analysis. We are developing various strategies to enhance the coherent SP radiation.