arXiv subjects

M. Lisowski

Publications and source records attributed to M. Lisowski.

4 recordsLinked to original sources

arXiv2000

Coherent phenomena in mesoscopic systems

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 self-sustaining currents can be obtained. The relation of quantum coherent state in mesoscopic cylinders to other coherent systems like superconductors is discussed.

cond-mat.mes-hall↗

arXiv1998

Possibility of long-range order in clean mesoscopic cylinders

A microscopic Hamiltonian of the magnetostatic interaction is discussed. This long-range interaction can play an important role in mesoscopic systems leading to an ordered ground state. The self-consistent mean field approximation of the magnetostatic interaction is performed to give an effective Hamiltonian from which the spontaneous, self-sustaining currents can be obtained. To go beyond the mean field approximation the mean square fluctuation of the total momentum is calculated and its influence on self-sustaining currents in mesoscopic cylinders with quasi-1D and quasi-2D conduction is considered. Then, by the use of the microscopic Hamiltonian of the magnetostatic interaction for a set of stacked rings, the problem of long-range order is discussed. The temperature $T^{*}$ below which the system is in an ordered state is determined.

cond-mat.mes-hall↗

arXiv1998

Orbital Magnetic Ordering in Disordered Mesoscopic Systems

We present some model calculations of persistent currents in disordered one- and two-dimensional mesoscopic systems. We use the tight-binding model and calculate numerically the currents in small systems for several values of disorder. Next we fit appropriate analytical formulae, and using them we find self- -sustaining currents and critical fields in larger, more realistic systems with different shapes of the Fermi surfaces.

cond-mat.mes-hall↗

arXiv1997

The Two-fluid Description of a Mesoscopic Cylinder

Quantum coherence of electrons interacting via the magnetostatic coupling and confined to a mesoscopic cylinder is discussed. The electromagnetic response of a system is studied. It is shown that the electromagnetic kernel has finite low frequency limit what implies infinite conductivity. It means that part of the electrons is in a coherent state and the system can be in general described by a two-fluid model. The coherent behavior is determind by the interplay between finite size effects and the correlations coming from the magnetostatic interactions (the interaction is considered in the mean field approximation). The related persistent currents depend on the geometry of the Fermi Surface. If the Fermi Surface has some flat portions the self-sustaining currents can be obtained. The relation of the quantum coherent state in mesoscopic cylinders to other coherent phenomena is discussed.

cond-mat.mes-hall↗