Berlin 2018 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 99: Poster Session: Transport
TT 99.13: Poster
Donnerstag, 15. März 2018, 15:00–19:00, Poster B
Shaping a single electron in a nanotube with an axial magnetic field — Magdalena Marganska1, Daniel R. Schmid2, Peter L. Stiller2, Alois Dirnaichner2, Christoph Strunk2, Milena Grifoni1, and •Andreas K. Hüttel2 — 1Institute for Theoretical Physics, University of Regensburg, 93053 Regensburg, Germany — 2Institute for Experimental and Applied Physics, University of Regensburg, 93053 Regensburg, Germany
Transport measurements on single wall carbon nanotubes allow fascinating insights into the interplay of molecular structure and electronic wave functions. Here, we analyze the magnetic field behaviour of quantum states in the limit of a single electron strongly confined to a quantum dot. An axial magnetic field (in the experiment up to 17T) exposes a very distinct behaviour of the two valleys. K’ valley states experience an increase of the tunnel coupling at low field, followed by subsequent decoupling. In contrast, K valley states decouple from the leads monotonically.
This phenomenon stems from the unique combination of cylindrical topology and honeycomb atomic lattice. Longitudinal and transversal momentum are coupled, allowing manipulation of the longitudinal electronic wave function via the Aharonov-Bohm phase. At zero field, the nanotube acts similar to a λ/4 resonator, where a wave function amplitude is finite near one of the contacts. A large magnetic field restores quantum box behaviour comparable to a λ/2 resonator, where the amplitude vanishes on both sides. This is directly reflected in the tunnel rates.