Semiconductor analog of the large persistent currents observed in small gold rings
✍ Scribed by George Kirczenow
- Publisher
- Elsevier Science
- Year
- 1993
- Tongue
- English
- Weight
- 211 KB
- Volume
- 14
- Category
- Article
- ISSN
- 0749-6036
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✦ Synopsis
The remarkably large persistent currents that are observed in disordered micron-scale gold rings at low temperatures have recently been explained in a theory of non-interacting electrons scattered by crystal grain boundaries. The present article examines the possibility that the basic physics underlying this explanation may also have observable consequences in a different system, a ballistic two-dimensional semiconductor ring with a potential barrier. It is predicted, using computer simulations, that such semiconductor rings can exhibit large persistent currents (\sim e v_{F} / L(L) is the ring circumference), despite the electron transmission probability through the barrier being small, in the regime of quantum-mechanical tunneling of electrons through the barrier. This, like the phenomenon observed in gold rings, is a manifestation of the fundamental dissimilarity of nonequilibrium transport phenomena and equilibrium persistent currents.