  Most of the half-Heusler RPtBi compounds (R=rare earth) host various surface
states due to spin-orbit coupling driven topological band structure. While
recent ARPES measurements ubiquitously reported the existence of surface states
in RPtBi, their evidence by other experimental techniques remains elusive. Here
we report the angle-dependent magnetic field response of electrical transport
properties of YPtBi in both the normal and superconducting states. The angle
dependence of both magnetoresistance and the superconducting upper critical
field breaks the rotational symmetry of the cubic crystal structure, and the
angle between the applied magnetic field and the measurement plane of a
plate-like sample prevails. Furthermore, the measured upper critical field is
notably higher than the bulk response for an in-plane magnetic field
configuration, suggesting the presence of quasi-2D superconductivity. Our work
suggests the transport properties cannot be explained solely by the bulk
carrier response, requiring robust normal and superconducting surface states to
flourish in YPtBi.
