  Materials with high carrier mobility showing large magnetoresistance (MR)
have recently received much attention because of potential applications in
future high-performance magneto-electric devices. Here, we report on the
discovery of an electron-hole-compensated half-Heusler semimetal LuPtBi that
exhibits an extremely high electron mobility of up to 79000 cm2/Vs with a
non-saturating positive MR as large as 3200% at 2 K. Remarkably, the mobility
at 300 K is found to exceed 10500 cm2/Vs, which is among the highest values
reported in three-dimensional bulk materials thus far. The clean Shubnikov-de
Haas quantum oscillation observed at low temperatures and the first-principles
calculations together indicate that the high electron mobility is due to a
rather small effective carrier mass caused by the distinctive band structure of
the crystal. Our finding provide a new approach for finding large,
high-mobility MR materials by designing an appropriate Fermi surface topology
starting from simple electron-hole-compensated semimetals.
