On the role of electron correlation and disorder on persistent currents in isolated one-dimensional rings

• Published in: Solid state communications Vol. 135; no. 4; pp. 278 - 283
• Main Authors: Maiti, Santanu K., Chowdhury, J., Karmakar, S.N.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-07-2005; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; D. Incommensurate potentials; D. Persistent current; E. Hubbard correlation; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in mesoscopic systems; Exact sciences and technology; Physics; 73.63.Nm; 73.23.−b; D. Persistent current; D. Incommensurate potentials; E. Hubbard correlation; 73.63.−b; 73.23.Ra; Magnetic flux; Disordered systems; 73.63.Nm D. Persistent current; Aharonov-Bohm effect; Incommensurate phases; 73.23.-b; Long-range order; Oscillations; Hubbard model; Persistent currents; Electron correlations; Transport processes; 73.63.-b
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2005.04.011

To understand the role of electron correlation and disorder on persistent currents in isolated 1D rings threaded by magnetic flux
ϕ, we study the behavior of persistent currents in aperiodic and ordered binary alloy rings. These systems may be regarded as disordered systems with well-defined long-range order so that we do not have to perform any configuration averaging of the physical quantities. We see that in the absence of interaction, disorder suppresses persistent currents by orders of magnitude and also removes its discontinuity as a function of
ϕ. As we introduce electron correlation, we get enhancement of the currents in certain disordered rings. Quite interestingly we observe that in some cases, electron correlation produces kink-like structures in the persistent current as a function of
ϕ. This may be considered as anomalous Aharonov–Bohm oscillations of the persistent current and recent experimental observations support such oscillations. We find that the persistent current converges with the size of the rings.