Quantum interference of relativistic electrons in the presence of magnetic fluxes

R. G. Chambers

Apostol Vourdas

Electron interference in the presence of non-classical time-dependent magnetic flux is studied. The quantum uncertainty Δϕ in the value of the non-classical magnetic flux plays a destructive role in the interference. The relative phase factor between the two electron beams is a quantum-mechanical operator, whose expectation value with regard to the density matrix describing the non-classical electromagnetic field determines the interference. A method similar to the Shapiro experiment in the context of Josephson junctions is used for the study of the details of this interference. Coherent states and squeezed states are considered and various interesting characteristics of the interference, which are associated to the quantum nature of these fields, are studied. The results are compared and contrasted with those in the classical case.

Mark P. Silverman

Silviu Olariu

This work studies the interference of electrons in the presence of a line of magnetic flux surrounded by a normal-conducting mesoscopic cylinder at low temperature. It is found that, while there is a supplementary phase contribution from each electron of the mesoscopic cylinder, the sum of these individual supplementary phases is equal to zero, so that the presence of a normal-conducting mesoscopic ring at low temperature does not change the Aharonov-Bohm interference pattern of the incident electron. It is shown that it is not possible to ascertain by experimental observation that the shielding electrons have responded to the field of an incident electron, and at the same time to preserve the interference pattern of the incident electron. It is also shown that the measuring of the transient magnetic field in the region between the two paths of an electron interference experiment with an accuracy at least equal to the magnetic field of the incident electron generates a phase uncertainty which destroys the interference pattern.

Gao Ying‐Fang, Yongping Zhang, Liang Jiu-Qing

The Aharonov–Bohm (AB) interference oscillations manifested through transmission of an electron in a mesoscopic device with a double-ring in the presence of a magnetic impurity serving as the spin-flipper are studied. The spin-flipper is demonstrated to indeed cause the partial decoherence of the AB interference. Moreover, it is found that the spin-up/down transmission coefficients are asymmetric in the flux reversal while the reflection coefficients as well as that the total transmission coefficient are symmetric.

Josuke Kuroiwa, Masumi Kasai, Toshifumi Futamase