  We study field-induced domain wall motion in permalloy nanowires with
vertically etched nanotrench pinning site. Micromagnetic simulations and
electrical measurements are employed to characterize the pinning potential at
the nanotrench. It is found that the potential profile for a transverse wall
significantly differs from that of a vortex wall, and there is a correlation
between the pinning strength and the potential profile. Reliable domain wall
pinning and depinning is experimentally observed from a nanotrench in permalloy
nanowires. This demonstrates the suitability of the proposed nanotrench pinning
sites for domain wall device applications.
