Quantum properties in transport through nanoscopic rings: Charge-spin separation and interference effects

K. Hallberg, Julian Rincon, S. Ramasesha

Research output: Chapter in Book/Report/Conference proceedingChapter

Abstract

Many of the most intriguing quantum effects are observed or could be measured in transport experiments through nanoscopic systems such as quantum dots, wires and rings formed by large molecules or arrays of quantum dots. In particular, the separation of charge and spin degrees of freedom and interference effects have important consequences in the conductivity through these systems. Charge–spin separation was predicted theoretically in one–dimensional strongly interacting systems (Luttinger liquids) and, although observed indirectly in several materials formed by chains of correlated electrons, it still lacks direct observation. We present results on transport properties through Aharonov–Bohm rings (pierced by a magnetic ux) with one or more channels represented by paradigmatic strongly–correlated models. For a wide range of parameters we observe characteristic dips in the conductance as a function of magnetic ux which are a signature of spin and charge separation. Interference effectSocould also be controlled in certain molecules and interesting prop–ertieSocould be observed. We analyze transport properties of conjugated molecules, benzene in particular, and that the conductance depends on the lead configuration. In molecules with translational symmetry, the conductance can be controlled by breaking or restoring this symmetry, e.g. by the application of a local external potential. These results open the possibility of observing these peculiar physical properties in anisotropic ladder systems and in real nanoscopic and molecular devices.

Original languageEnglish (US)
Title of host publicationCondensed Matter Theories
PublisherWorld Scientific Publishing Co.
Pages186-196
Number of pages11
ISBN (Electronic)9789814340793
ISBN (Print)9814340782, 9789814340786
DOIs
StatePublished - Jan 1 2011
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

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