A. Fujimoto et al., Comparison of magnetoconductance of the delta-doped layer and bulk crystalof Si : Sb in the weak localization regime, PHYSICA B, 302, 2001, pp. 7-11
The magnetoresistance of a Si:Sb delta -doped layer has been measured in ma
gnetic fields up to 3.4 T. The results have been compared with those for a
heavily doped bulk sample. The portion of the occupation of Sb in delta -do
ped layer is 0.11 monolayer. We have observed the positive magnetoresistanc
e in the perpendicular weak magnetic fields arising from the weak anti-loca
lization due to spin-orbit interaction for the first time in this system. T
he ratio of spin-orbit scattering time to inelastic scattering time is fair
ly large compared with that of the metallic thin films which include heavy
elements. When the moderate magnetic field is applied perpendicularly to th
e layer, the negative magnetoresistance appears. On the other hand, the pos
itive one is observed in parallel fields. The comparative analyses are perf
ormed between the two kinds of samples within the framework of weak localiz
ation theories. (C) 2001 Elsevier Science B.V. All rights reserved.