Aharonov–Bohm oscillations in disordered nanorings with quantum dots: Effect of electron–electron interactions

Abstract

We investigate the effect of electron-electron interactions on Aharonov-Bohm (AB) current oscillations in nanorings formed by a chain of metallic quantum dots. We demonstrate that electron-electron interactions cause electron dephasing thereby suppressing the amplitude of AB oscillations at all temperatures down to T = 0. The crossover between thermal and quantum dephasing is found to be controlled by the ring perimeter. Our predictions can be directly tested in future experiments.Averaging over such random phases usually washes out AB oscillations δG(Φ) with the period Φ0 in the presence of disorder [1]. There exists, however, a special class of electron trajectories which interference is not sensitive to averaging over disorder. These are pairs of time-reversed paths which are also responsible for the phenomenon of weak localization [2]. In disordered rings interference between these trajectories gives rise to non-vanishing AB oscillations with the principal period Φ0/2. Such oscillations will be analyzed below in this paper.It is well established that interactions between electrons and other degrees of freedom can lead to their decoherence thus reducing electron's ability to interfere. Hence, AB oscillations can be used as a tool to probe the fundamental effect of interactions on quantum coherence of electrons in nanoscale conductors.Recently it was demonstrated [3,4,5] that the effect of quantum decoherence by electron-electron interactions

Weak localization, Aharonov-Bohm oscillations, and decoherence in arrays of quantum dots

“…In this paper we will review and extend our analysis of weak localization effects and Aharonov-Bohm oscillations in systems composed of metallic quantum dots [23][24][25][26][27] . In Sec.…”