Robust edge photocurrent response on layered Type II Weyl semimetal WTe2

we demonstrate robust photocurrent generation at the edge of Td-WTe2, due to crystalline-symmetry breaking along certain crystal fracture directions and possibly enhanced by robust fermi-arc type surface states. The edge current response is robust over a wide excitation photon energy and this robust feature shall arise universally in a wide class of quantum materials with similar crystal symmetries. The edge current response demonstrated in this work provides a charge separation mechanism for photosensing over broad wavelength range.