Oscillatory Anisotropic Magnetoresistance Arising From Quantum Well States in Au/Fe(001) Bilayers

The anisotropic magnetoresistance (AMR) in epitaxial Au/Fe(001) bilayers grown on MgO(001) substrate was systematically studied as a function of Au thickness over the temperature range 6300K. The AMR oscillates with a period of about 1.8 nm in Au thickness at low temperatures and also oscillates at certain higher temperatures. Such novel oscillatory AMR behavior is attributed to quantum well states in Au ultrathin films.