AVOIDED CROSSINGS OF AU(111) AG/AU/AG DOUBLE-QUANTUM-WELL STATES/

A Ag8/Au3/Ag(x) double quantum well is grown on Au(111) to form two Ag quantum wells coupled through a thin Au barrier layer, and the electr onic structure of this system is examined with angle-resolved photoemi ssion. As the thickness of the outer well (x, in monolayers) is varied , the measured binding energies of the quantum-well states show an avo ided-crossing behavior, in good agreement with a model calculation bas ed on Bloch wave functions. The results demonstrate the effect of elec tronic translayer coupling.