Time-dependent studies in mesoscopic systems: Photo current, AC current and current fluctuations
Abstract
In this thesis we study the response of mesoscopic systems to time dependent fields and the current fluctuations in mesoscopic systems with a superconducting region. Using the non equilibrium Greens function formalism we derive general expressions for the photo current and the ac current in terms of double energy Greens functions. The effects of phase-breaking and charging can be included. The formalism is used to study the effect of charging on the ac conductance of double barrier resonant tunneling structures. Charging is found to play a significant role in determining the ac conductance. Simple examples are used to illustrate the effect of phonon scattering on the ac response of resonant tunneling structures. We then study the current fluctuations in mesoscopic systems with a superconducting region using the Landauer-Buttiker approach to transport. Expressions for current fluctuations analogous to those in purely normal mesoscopic systems are derived. These expressions are applied to some simple examples.
Degree
Ph.D.
Advisors
Datta, Purdue University.
Subject Area
Electrical engineering|Condensation|Electromagnetism
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