Browsing by Subject "Metallic ring"

Now showing 1 - 2 of 2

Open Access
Aharonov-Bohm effect induced by light
(Springer, Dordrecht, 1998) Kulik, Igor O.; Shumovsky, Alexander S.; Hunter, G.; Jeffers, S.; Vigier, J. -P.
The quantum interferometry of normal metallic loops based on the Aharonov-Bohm effect is usually applied to measurements at low temperatures in the case of static or slowly time-varying magnetic fields (e.g., see [1]). Recently, an important case of an ac field of high frequency ω » v F /R (v F is the Fermi velocity and R is the radius of the metallic ring) has been considered [2]. This consideration is based on the assumption that the position dependent time-varying electromagnetic field produces the static electron energy minibands in the ring which appear due to electron motion in a time-averaged electrostatic potential periodic with coordinate along the ring circumference, produced by the square of an ac electric field [3]. it should be noted that, in the quantum case, an electron reflection from an oscillating potential causes a time-dependent phase shift, resulting in an effective chaotization of the phase of electron wave function, except at energy multiples of ħω.
Open Access
Persistent currents in mesoscopic loops and networks
(TÜBİTAK, 2003) Kulik, Igor O.
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 Φ 0 = 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 Φ 0. Extremely small (nanoscopic, macromolecular) loop with three localization sites at flux Φ = Φ 0/2 develops a Λ-shaped energy configuration suitable to serve as a qubit, as well as at the same 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.