Superconducting gap anisotropy in Nd1.85Ce0.15CuO4: Results from photoemission

We have performed angle resolved photoelectron spectroscopy on the electron doped cuprate superconductor Nd1.85Ce0.15CuO4 A comparison of the leading edge midpoints between the superconducting and normal states reveals a smal l, but finite shift of 1.5-2 meV near the (pi ,0) position, but no observab le shift along the zone diagonal near (pi /2,pi /2). This is interpreted as evidence For an anisotropic superconducting gap in the electron doped mate rials, which is consistent with the presence of d-wave superconducting orde r in this cuprate superconductor.