Harold Grubin

Physics

Research Interests

Solid state device physics. Studies focus on time dependent physical instabilities in solid state electronic devices through analysis and transient self-consistent numerical simulations of the Boltzmann transport, density matrix and Wigner function equations. Self-consistency means Poisson’s equation is solved simultaneously with the transport equations. Numerical simulation of solid state electronic devices began in earnest during the sixties with transient studies of Gunn diodes, and continued thereafter with studies of compound and elemental semiconductor transistors, quantum tunneling structures and spin dependent structures. Numerical simulation provided a convincing picture of the formation and stability of traveling dipole layers, and taught us that treating diodes as ideal objects was unlikely ever to provide an explanation of the richness of experimental observation. Because the size of devices studied span the micron to nanometer scales at frequencies ranging from GHz to THz, the device plus the contacts plus detailed device structure properties needs to be treated simultaneously. Because the finite time duration of collisions can be a non-negligible fraction of the device switching time and the details of the measuring circuit can alter the tunneling times of the carriers, large signal transient analysis is required. Our studies have included size effects, large signal transients, and the effects of the measuring circuit. Each of these studies has been generalized to include spin-dependent transport, with the spin population altered through the inclusion of dilute magnetic semiconductors in the tunneling and superlattice structures. Topics that will be studied include the consequences of the breakdown of the Fermi Golden rule where the time scales of interest are of the order of the time for a scattering transition to occur, and the intra-collisional field effect where the carriers gain energy from the field during the time duration of a collision.

Education

• Ph.D., Physics, Polytechnic Institute of Brooklyn, Brooklyn, NY, 1967
• M.Sc., Physics, Polytechnic Institute of Brooklyn, Brooklyn, NY, 1962
• B.Sc., Mathematics, Brooklyn College, Brooklyn, NY, 1960

Experience

• 2007-present: President, NanoRTD, a small business with emphasis on the operation of THz sources based on quantum tunneling devices
• 2006-present: Research Professor of Physics, Department of Physics, University of Connecticut
• 2001-2005: Research Professor of Physics, University of Hartford
• 1981-2004: Scientific Research Associates, Inc (President 1997-2004)
• 1966-1981: United Technologies Research Center, Senior Theoretical Physicist

Professional Societies

• American Physical Society
• Institute of Electrical and Electronics Engineers
• American Association for the Advancement of Science

Honors

• International Co-editor of John Wiley & Sons Series on Design and Measurement in Electronic Engineering
• Co-director of NATO Advanced Study Institute on Quantum Transport in Ultrasmall Devices