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Coulomb correlations and coherent charge tunneling in mesoscopic coupled rings

C. M. Canali·W. Stephan·L. Y. Gorelik·R. I. Shekhter·M. Jonson
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Abstract

We study the effect of a strong electron-electron (e-e) interaction in a system of two concentric one-dimensional rings with incommensurate areas A_1 and A_2, coupled by a tunnel amplitude. For noninteracting particles the magnetic moment (persistent current) m of the many-body ground state and first excited states is an irregular function of the external magnetic field. In contrast, we show that when strong e-e interactions are present the magnetic field dependence of m becomes periodic. In such a strongly correlated system disorder can only be caused by inter-ring charge fluctuations, controllable by a gate voltage. The oscillation period of m is proportional to 1/(A_1 + A_2) if fluctuations are suppressed. Coherent inter-ring tunneling doubles the period when charge fluctuations are allowed.

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C. M. Canali, W. Stephan, L. Y. Gorelik, R. I. Shekhter, M. Jonson. 1997-10-22. Coulomb correlations and coherent charge tunneling in mesoscopic coupled rings. https://doi.org/10.1209/epl%2Fi1997-00425-9

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