Terahertz magnetotransport measurements in underdoped Pr2-xCexCuO4 and comparison with angle-resolved photoemission

We present magnetotransport measurements performed on underdoped Pr2-xCexCuO4 at THz frequencies as a function of temperature and doping. A rapidly decreasing Hall mass is observed as the doping is reduced consistent with the formation of small electron Fermi pockets. However, both dc and infrared magnetotransport data strongly deviate from the predictions of transport theory within the relaxation-time approximation based on angular-resolved photoemission data. Furthermore, the Hall mass remains negative with no signature of a change in Fermi-surface topology at or above the Neacuteel temperature and the characteristic temperature at which the optical gap fully closes. In the paramagnetic state, this behavior of the Hall mass may be qualitatively understood as arising from current vertex corrections to the Hall conductivity due to magnetic fluctuations as observed in overdoped Pr2-xCexCuO4 [G. S. Jenkins , arXiv:0901.1701 (unpublished)].