Interface transparency to orbital current

Orbitronics is an exciting new field closely connected to spintronics. One of the important questions is how efficiently orbital currents can be transferred across interfaces. Here, the authors study spin-orbit torque in Cr/Ni bilayers with the insertion of an ultrathin spacer between them. Using the experimentally measured torque as a proxy for the orbital current transferred from Cr to Ni, they find that across 12 different spacer materials, the apparent interface transparency to the orbital current is comparable to or larger than the spin current.