  In a system accommodating both surface and bulk conduction channels, a
long-standing challenge is to extract weak Shubnikov-de Haas oscillation signal
in the surface from a large background stemming from the bulk. Conventional
methods to suppress the bulk conduction often involve doping, an intrusive
approach, to reduce the bulk carrier density. Here we propose a geometric
method, i.e. attaching a metal shunt to the indium arsenide epilayer, to
redistribute current and thus enhance the oscillation-to-background ratio. This
allows us, for the first time, to observe clear quantum oscillations and
nonzero Berry's phase at the surface of indium arsenide. We also identify the
existence of a Rashba type spin-orbit interaction, on the InAs surface, with a
large coupling constant ~ 1 eVA. We anticipate wide applicability of this
non-intrusive architecture in similar systems such as topological insulators.
