  WTe2, as a type-II Weyl semimetal, has 2D Fermi arcs on the (001) surface in
the bulk and 1D helical edge states in its monolayer. These features have
recently attracted wide attention in condensed matter physics. However, in the
intermediate regime between the bulk and monolayer, the edge states have not
been resolved owing to its closed band gap which makes the bulk states
dominant. Here, we report the signatures of the edge superconductivity by
superconducting quantum interference measurements in multilayer WTe2 Josephson
junctions and we directly map the localized supercurrent. In thick WTe2 (~60
nm), the supercurrent is uniformly distributed by bulk states with symmetric
Josephson effect ($\left|I_c^+(B)\right|=\left|I_c^-(B)\right|$). In thin WTe2
(10 nm), however, the supercurrent becomes confined to the edge and its width
reaches up to 1.4 um and exhibits non-symmetric behavior
$\left|I_c^+(B)\right|\neq \left|I_c^-(B)\right|$. The ability to tune the edge
domination by changing thickness and the edge superconductivity establishes
WTe2 as a promising topological system with exotic quantum phases and a rich
physics.
