Absence of Significant Spin-Current Generation in Ti/Fe−Co−B Bilayers with Strong Interfacial Spin-Orbit Coupling

Efficient generation of spin current is fundamental in spintronics. Despite a decade and more of intense research interest, whether the spin-orbit coupling (SOC) effects of magnetic interfaces can effectively generate a spin current remains an open question. Utilizing Ti/Fe-Co-B bilayers with negligible bulk spin Hall effect and strong, tunable interfacial SOC, the authors establish clean experimental evidence that magnetic interfaces $d\phantom{\rule{0}{0ex}}o$ $n\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}t$ generate any significant spin current via spin-orbit filtering or Rashba-Edelstein-like) effects.