We report measurements of Shubnikov-de Haas (SdH) oscillations in single crystals of BiTeCl at magnetic fields up to 31 T and at temperatures as low as 0.4 K. Two oscillation frequencies were resolved at the lowest temperatures, $F_{1}=65 pm 4$ Tesla
and $F_{2}=156 pm 5$ Tesla. We also measured the infrared optical reflectance $left(cal R(omega)right)$ and Hall effect; we propose that the two frequencies correspond respectively to the inner and outer Fermi sheets of the Rashba spin-split bulk conduction band. The bulk carrier concentration was $n_{e}approx1times10^{19}$ cm$^{-3}$ and the effective masses $m_{1}^{*}=0.20 m_{0}$ for the inner and $m_{2}^{*}=0.27 m_{0}$ for the outer sheet. Surprisingly, despite its low effective mass, we found that the amplitude of $F_{2}$ is very rapidly suppressed with increasing temperature, being almost undetectable above $Tapprox4$ K.
Temperature dependent transport measurements on ultrathin antiferromagnetic Mn films reveal a heretofore unknown non-universal weak localization correction to the conductivity which extends to disorder strengths greater than 100 k$Omega$ per square.
The inelastic scattering of electrons off of gapped antiferromagnetic spin waves gives rise to an inelastic scattering length which is short enough to place the system in the 3d regime. The extracted fitting parameters provide estimates of the energy gap ($Delta = 16$ K) and exchange energy ($bar{J} = 320$ K).
