title: The Friedel sum rule at Fano resonances.
abstract: If a mesoscopic system is non-chaotic or non-ergodic then the thermodynamic and transport properties do not depend on the impurity averaged density of states. We show that the partial density of states as well as the density of states of a given system with a given impurity configuration can be determined exactly from the asymptotic wavefunction (or scattering matrix) at the resonances. The asymptotic wavefunction can be determined experimentally without any knowledge about the quantum mechanical potential (including electron-electron interaction) or wavefunction in the interior of the system. Some counterintuitive relations derived here allow this.
authors.affiliation: Unit for Nano Science and Technology, S N Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake City, Kolkata 98, India.
authors.forename: P
authors.initials: P
authors.lastname: Singha Deo