Europhys. Lett.
Volume 74, Number 5, June 2006
Page(s) 882 - 888
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 10 May 2006
Europhys. Lett., 74 (5), pp. 882-888 (2006)
DOI: 10.1209/epl/i2006-10042-8

Total angular momentum conservation during tunnelling through semiconductor barriers

U. Gennser1, M. Scheinert2, L. Diehl2, 3, S. Tsujino2, A. Borak2, C. V. Falub2, D. Grützmacher2, A. Weber2, D. K. Maude4, G. Scalari5, Y. Campidelli6, O. Kermarrec6 and D. Bensahel6

1  CNRS-LPN - Route de Nozay, F-91460 Marcsoussis, France
2  Paul Scherrer Institut - CH-5232 Villigen, Switzerland
3  Division of Engineering and Applied Sciences, Harvard University Cambridge, MA 02138, USA
4  GHMFL, CNRS - F-38042 Grenoble, France
5  Université de Neuchâtel - CH-2000 Neuchâtel, Switzerland
6  STMicroelectronics - F-38926 Crolles Cedex, France

received 9 January 2006; accepted in final form 12 April 2006
published online 10 May 2006

We have investigated the electrical transport through strained p-type $\ab{Si}/\ab{Si}_{1-x}\ab{Ge}_x$ double-barrier resonant tunnelling diodes. The confinement shift for diodes with different well width, the shift due to a central potential spike in a well, and magnetotunnelling spectroscopy demonstrate that the first two resonances are due to tunnelling through heavy-hole levels, whereas there is no sign of tunnelling through the first light-hole state. This establishes for the first time the conservation of the total angular momentum in valence band resonant tunnelling. It is also shown that conduction through light-hole states is possible in many structures due to tunnelling of carriers from bulk emitter states.

72.25.Dc - Spin polarized transport in semiconductors.
73.40.Gk - Tunneling.

© EDP Sciences 2006