Regensburg 1998 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
HL: Halbleiterphysik
HL 29: Transporteigenschaften
HL 29.10: Vortrag
Donnerstag, 26. März 1998, 12:45–13:00, H17
Electron Transport Through an Asymmetric Microjunction -A Ballistic Rectifier- — •A.M. Song1, A. Lorke1, J.P. Kotthaus1, W. Wegscheider2, and M. Bichler2 — 1Sektion Physik der LMU, Geschwister-Scholl Platz 1, 80539 M"unchen — 2Walter-Schottky-Institut der TUM, 85748 Garching
We investigate the nonlinear ballistic electron transport in semiconductor microjunctions with a broken inversion symmetry fabricated on a GaAs/AlGaAs heterostructure. In a cross junction with lateral dimensions well below the elastic mean free path, we introduce an asymmetric artificial scatterer. We demonstrate that this causes pronounced nonlinear behavior such that the four-probe resistances Rij,kl(I)≈ −Rij,kl(−I) and Rij,kl(B) ≫ Rkl,ij(B) even in zero magnetic field. Our device geometry thus allows for a successful guidance of electrons to a predetermined spatial direction, independent of the input current direction. As a result, the device works as a ballistic rectifier with a mechanism entirely different from an ordinary semiconductor diode-based rectifier. An extended Landauer-B"uttiker formula, which includes the dependence of the transmission coefficients on lead currents, qualitatively describes our data. The experiment demonstrates and emphasizes the possibility of introducing artificial scatterers in semiconductor microstructures to tailor their ballistic transport properties for desired device applications.