Quantum Persistent Currents
Persistent currents are those, which, as its name states, do not change in time. It is a quantum effect revealed in microscopic and mesoscopic systems, in which a charged particle moves around a close geometry, such as a ring, in the presence of a magnetic flux. The calculation of the persistent current in a ring with several electrons can be reduced from the calculation of the current associated with the energy of an electron, summing over these currents. The simplest model is a metal ring, and a current generated by a single electron. The currents are the slopes of the for each energy level. Each of the slopes of successive levels are anti-correlated, the current of each electron level added to the ring will tend to cancel the contribution of the previous level, resulting in a current essentially dominated by the highest energy level.