Tunable spin-gaps in a quantum-confined geometry
  We have studied the interplay of a giant spin-orbit splitting and of quantum confinement in artificial Bi-Ag-Si trilayer structures. Angle-resolved photoelectron spectroscopy (ARPES) reveals the formation of a complex spin-dependent gap structure, which can be tuned by varying the thickness of the Ag buffer layer. This provides a means to tailor the electronic structure at the Fermi energy, with potential applications for silicon-compatible spintronic devices. 
Emmanouil Frantzeskakis, Stephane Pons, Hossein Mirhosseini, Jurgen   Henk, Christian. R. Ast, and Marco Grioni