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

Abstract

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.

Quantum Transport in Mesoscopic Ring Structures: Effects of Impurities, Long-Range Hopping and Interactions

“…To explore the role of disorder and electron-electron correlation on persistent current, in this sub-section, we focus our attention on certain systems which closely resemble to the disordered systems where we do not require any configuration averaging 64 . These are chemically modulated structures possessing well-defined longrange order and as specific examples we consider aperiodic and ordered binary alloy rings.…”

Persistent Current in Metallic Rings and Cylinders

“…But the inclusion of the electron correlation [33] doesn't give any significant enhancement of the persistent current. Later, in some recent papers [34,35,36] it has been studied that the simplest nearest-neighbor tight-binding model with electron-electron interaction cannot explain the actual mechanisms.…”

Magneto-transport in a quantum network: evidence of a mesoscopic switch

“…Persistent current being one such exotic quantum mechanical phenomenon observed in normal metal mesoscopic rings and nanotubes pierced by Aharonov-Bohm (AB) flux φ. Prior to its experimental evidence, the possibility of a non-decaying current in normal metal rings was first predicted by Büttiker, Imry and Landauer 3 in a pioneering work, and, in the sub-sequent years theoretical attempts were made [4][5][6][7][8][9][10][11][12][13][14][15][16][17] to understand the actual mechanism behind it. The experimental realization of this phenomenon of non-decaying current in metallic rings/cylinders has been established quite in late.…”