The phosphorus delta-layers fabricated by a
phosphine exposure followed by Si epitaxial overgrowth proves
to be a novel 2 dimensional electron gas (2DEG) system. The
strong impurity scattering in this system offers an interesting
example of weak electron localization. The figure above shows
zero-magnetic field conductivity decreasing logarithmically
with temperature, as expected for a 2D metal. Negative magnetoresistance
in a perpendicular magnetic field, as shown in the inset,
further supports the weak localization interpretation.
[Appl. Phys. Lett. 80, 1580-1582 (2002).]
