University of Konstanz
Graduiertenkolleg / PhD Program
Computer and Information Science

Colloquium of the Department and the PhD Program

title

Quantum Circuit Theory and Quantum Kirchhoff Rules for Nanoelectronics

speaker

Prof. Dr. Wolfgang Belzig, University of Konstanz, Germany

date & place

Wednesday, 01.02.2012, 16:15 h
Room C 252

abstract

Electronic conduction properties are conveniently described by conservation laws for electric charge and energy. In a finite element approach the conservation laws are cast into the simple so-called Kirchhoff rules, allowing to construct complicated devices, such as state-of-the-art computers. Upon decreasing the device size and considering phenomena like superconductivity or spin coherence, quantum effects become more prominent and need to be considered. In this talk I will outline a general quantum circuit theory developed by Nazarov, which is applicable to a large variety of electronic configurations. The method allows to cover quantum interference and spin coherence in realistic circuits. I will illustrate with examples how the quantum nature of electrons shows up in practically measurable current-voltage characteristics.