Coherent phenomena in mesoscopic systems

Abstract

A mesoscopic system of cylindrical geometry made of a metal or a semiconductor is shown to exhibit features of a quantum coherent state. It is shown that magnetostatic interaction can play an important role in mesoscopic systems leading to an ordered ground state. The temperature T * below the system exhibits long-range order is determined. The self-consistent mean field approximation of the magnetostatic interaction is performed giving the effective Hamiltonian from which the selfsustaining currents can be obtained.The relation of quantum coherent state in mesoscopic cylinders to other coherent systems like superconductors is discussed.