Interplay of the Aharonov-Bohm effect and Klein tunneling in graphene
| Autor: | Bjoern Trauzettel, Dan Bohr, Joerg Schelter |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2010 |
| Předmět: |
Physics
Smoothness (probability theory) Condensed matter physics Condensed Matter - Mesoscale and Nanoscale Physics Graphene Scanning tunneling spectroscopy Klein paradox Condensed Matter Physics Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Electronic Optical and Magnetic Materials law.invention symbols.namesake Amplitude law Quantum mechanics Condensed Matter::Superconductivity symbols Order (group theory) Aharonov–Bohm effect Quantum tunnelling |
| Popis: | We numerically investigate the effect of Klein tunneling on the Aharonov-Bohm oscillations in graphene rings using a tight-binding model with nearest-neighbor couplings. In order to introduce Klein tunneling into the system, we apply an electrostatic potential to one of the arms of the ring, such that this arm together with the two adjacent leads form either a $nn'n$- or $npn$-junction ($n,n'$: conduction band transport, $p$: valence band transport). The former case corresponds to normal tunneling and the latter case to Klein tunneling. We find that the transmission properties strongly depend on the smoothness of the $pn$-interfaces. In particular, for sharp junctions the amplitude profile is symmetric around the charge neutrality point in the gated arm, whereas for smooth junctions the Aharonov-Bohm oscillations are strongly suppressed in the Klein tunneling as compared to the normal tunneling regime. Comment: 7 pages, 9 figures; revised version (minor improvements to the text, replaced Fig. 7); to be published in Physical Review B |
| Databáze: | OpenAIRE |
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