  Electrostatically defined nanoscale devices on two-dimensional semiconductor
heterostructures are the building blocks of various quantum electrical
circuits. Owing to its atomically flat interfaces and the inherent
two-dimensional nature, van der Waals heterostructures hold the advantage of
large-scale uniformity, flexibility and portability over the conventional bulk
semiconductor heterostructures. In this letter we show the operation of a
split-gate defined point contact device on a MoS2/h-BN heterostructure, a first
step towards realizing electrostatically gated quantum circuits on van der
Waals semiconductors. Our devices show signatures of channelized electron flow
and a complete shutdown of transport similar to the conventional point contacts
defined on bulk semiconductor heterostructures. We explore the role of
back-gate and the drain-source voltages on the pinch-off characteristics and,
we are able to tune the pinch-off characteristics by varying the back-gate
voltage at temperatures ranging from 4K to 300 K.
