Large magnetoresistance and quantum oscillations in SnPbTe.

We have synthesized high-quality single crystals of SnPbTe and carried out detailed studies of the magnetotransport properties of one of the samples, SnPbTe. Longitudinal magnetoresistance increases almost linearly with increasing applied field () and reaches ∼310% at= 13 T. At higher fields, both longitudinal and Hall resistance show clear Shubnikov de Haas oscillations. The oscillations are smooth and periodic, and there exists only one frequency,∼ 57 T. However, an additional frequency,∼ 69 T, appears as the angle between the field direction and the normal to the sample surface () is increased. Bothandexhibit-dependence;decreases whereasincreases gradually with increasing. The presence of two frequencies in SnPbTe indicates that there exist two Fermi surface pockets (andpockets). We have constructed the Landau-level fan plot and determined the Berry phase () for thepocket to be∼ 0.1. Thisvalue is very close to the expected value of 0 for a topologically trivial system.