MAGNETOTRANSPORT PHENOMENA IN SINGLE ALGAAS GAAS QUANTUM WIRES GROWN ON LATERALLY PATTERNED SUBSTRATES/

Citation
M. Tornow et al., MAGNETOTRANSPORT PHENOMENA IN SINGLE ALGAAS GAAS QUANTUM WIRES GROWN ON LATERALLY PATTERNED SUBSTRATES/, Solid-state electronics, 40(1-8), 1996, pp. 323-328
Citations number
18
Categorie Soggetti
Engineering, Eletrical & Electronic","Physics, Applied","Physics, Condensed Matter
Journal title
ISSN journal
00381101
Volume
40
Issue
1-8
Year of publication
1996
Pages
323 - 328
Database
ISI
SICI code
0038-1101(1996)40:1-8<323:MPISAG>2.0.ZU;2-O
Abstract
Single, sub-micrometer wide quantum wires have been fabricated using m olecular beam epitaxy on mesa-etched GaAs substrates, where the GaAs w ire is embedded in AlGaAs. By using a Hall bar pattern, potential prob es were directly attached to the wires while grown. To avoid problems associated with anisotropic etching and regrowth, the wire structures were oriented along the [100] crystallographic directions. From this f abrication technique, described in detail by Shitara et al., Appl. Phy s. Lett. 66, 2385 (1995), one can expect the formation of high quality ''self-aligned'' quantum wires with a confinement potential determine d by the conduction band discontinuity of AlGaAs and GaAs, Here we stu dy the four-point magnetoresistance of 50 mu m long single quantum wir es with widths between 250 and 700 nm from 1.3 to 21 K. A distinct wea k localization peak and universal conductance fluctuations dominate th e low magnetic field regime and are used to estimate the phase-coheren ce length of the electrons. Pronounced 1/B periodic quantum oscillatio ns at magnetic fields above 1 T are consistent with the picture of wir es with a square-well shaped confining potential.