31-05-2012, 12:32 PM
Theory of the Fano Effect and Quantum Mirage
Theory of the Fano Effect and Quantum Mirage.ppt (Size: 1.24 MB / Downloads: 53)
Basic ingredients
STM tip - Feature-less band
Surface states - Two-dimensional band
Bulk states - Three-dimensional band
Magnetic adatom - An Anderson impurity
Recap of the main experimental findings
There is a quantum mirage when a Co atom is placed at one of the foci.
No mirage when the Co atom is placed away from the foci.
The quantum mirage oscillates with 4kFa.
The magnitude of the mirage depends only weakly on the ellipse eccentricity.
Theoretical model
Cu(111) surface states form a 2DEG with a Fermi energy of EF=450meV and kF-1=4.75 angstroms.
Free 3D conduction-electron bulk states.
Each Co atom is modeled by a nondegenerate Anderson impurity.
Hybridization with both surface and bulk states.