Persistent Currents in Mesoscopic Loops and Networks
Authors : Igor O. Kulik
Pages : 395-418
Doi:10.3906/sag-1112-50
View : 10 | Download : 6
Publication Date : 9999-12-31
Article Type : Makaleler
Abstract :The paper describes persistent (also termed ``permanent", or ``non-decaying") currents in mesoscopic metallic and macromolecular rings, cylinders and networks. The current arises as a response of system to Aharonov-Bohm flux threading the conducting loop and does not require external voltage to support the current. Magnitude of the current is periodic function of magnetic flux with a period of normal-metal flux quantum F0 = hc/e. Spontaneous persistent currents arise in regular macromolecular structure without the Aharonov-Bohm flux provided the azimuthal periodicity of the ring is insured by strong coupling to periodic background (a ``substrate"), otherwise the system will undergo the Peierls transition arrested at certain flux value smaller than F0. Extremely small (nanoscopic, macromolecular) loop with three localization sites at flux F = F0/2 develops a L-shaped energy configuration suitable to serve as a qubit, as well as at the same time as a ``qugate" (quantum logic gate) supporting full set of quantum transitions required for universal quantum computation. The difference of the Aharonov-Bohm qubit from another suggested condensed-matter quantum computational tools is in the radiation free couplings in a qubit supporting the scalable, long-lived quantum computation.Keywords : Turk. J. Phys., 27, (2003), 395-418. Full text: pdf Other articles published in the same issue: Turk. J. Phys., vol.27, iss.5.