QUANTIZED CONDUCTANCE IN A SI SI0.7GE0.3 SPLIT-GATE DEVICE AND IMPURITY-RELATED MAGNETOTRANSPORT PHENOMENA/

Authors
TOBBEN D WHARAM DA ABSTREITER G KOTTHAUS JP SCHAFFLER F
Citation
D. Tobben et al., QUANTIZED CONDUCTANCE IN A SI SI0.7GE0.3 SPLIT-GATE DEVICE AND IMPURITY-RELATED MAGNETOTRANSPORT PHENOMENA/, Solid-state electronics, 40(1-8), 1996, pp. 405-408
Citations number
17
Categorie Soggetti
Engineering, Eletrical & Electronic","Physics, Applied","Physics, Condensed Matter
Journal title
Solid-state electronics → ACNP
ISSN journal
00381101
Volume
40
Issue
1-8
Year of publication
1996
Pages
405 - 408
Database
ISI
SICI code
0038-1101(1996)40:1-8<405:QCIASS>2.0.ZU;2-P
Abstract
We have defined a quantum point-contact by the split-gate technique in a Si/SiGe heterostructure containing a two-dimensional electron gas w ith an elastic mean free path of about 1.3 mu m. The conductance of th is device shows typical steps very close to multiples of 4e(2) h(-1). Upon application of a perpendicular magnetic field the spin and valley degeneracies are lifted and magnetic depopulation of the one-dimensio nal subbands can be observed. The appearance of Aharonov-Bohm oscillat ions for B greater than or equal to 2 T and of resonant tunneling peak s close to ''pinch-off'' indicates the presence of impurities close to the constriction.