Giant Spin Splitting through Surface Alloying

TLDR

Surface alloying generates electronic states with exceptionally large spin splitting. The study examines the implications of these materials for spintronics and fundamental physics. Using a long‑range ordered Bi/Ag(111) surface alloy with up to 1 eV band separation, the authors employ ARPES to probe the quasi‑one‑dimensional density of states near the band edge. Low‑temperature scanning tunneling spectroscopy reveals the predicted singularity in the local density of states.

Abstract

Surface alloying is shown to produce electronic states with a very large spin-splitting. We discuss the long range ordered bismuth/silver(111) surface alloy where an energy bands separation of up to one eV is achieved. Such strong spin-splitting enables angular resolved photoemission spectroscopy to directly observe the region close to the band edge, where the density of states shows quasi-one dimensional behavior. The associated singularity in the local density of states has been measured by low temperature scanning tunneling spectroscopy. The implications of this new class of materials for potential spintronics applications as well as fundamental issues are discussed.