Low field magnetotransport revealing signatures of ballistic transport effects in strained Si/SiGe cavities is investigated. We fabricated strained Si/SiGe cavities by confining a high mobility Si/SiGe 2DEG in a bended nanowire geometry defined by electron-beam lithography and reactive ion etching. The main features observed in the low temperature magnetoresistance curves are the presence of a zero-field magnetoresistance peak and of an oscillatory structure at low fields. By adopting a simple geometrical model we explain the oscillatory structure in terms of electron magnetic focusing. A detailed examination of the zero-field peak lineshape clearly shows deviations from the predictions of ballistic weak localization theory.
@article{arxiv.cond-mat/0411415,
title = {Low field magnetotransport in strained Si/SiGe cavities},
author = {G. Scappucci and L. Di Gaspare and F. Evangelisti and E. Giovine and A. Notargiacomo and R. Leoni and V. Piazza and P. Pingue and F. Beltram},
journal= {arXiv preprint arXiv:cond-mat/0411415},
year = {2009}
}
Comments
Submitted to Physical Review B, 25 pages, 7 figures