Controlled interaction of surface quantum-well electronic states.
We report on the construction of well-defined surface quantum well arrangements by combining self-assembly protocols and molecular manipulation procedures. After the controlled removal of individual porphyrin molecules from dense-packed arrays on Ag(111), the surface state electrons are confined at the bare silver patches. These act as quantum wells that show well-defined unoccupied bound surface states. Scanning tunneling spectroscopy and complementary boundary element method calculations are performed to characterize the interaction between the bound states of adjacent quantum wells and reveal a hybridization of wave functions resulting in bonding and antibonding states. The interwell coupling can be tuned by the deliberate choice of the molecules acting as potential barriers. The fabrication method is shown to be ideally suited to engineer specific configurations as one-dimensional chains or two-dimensional artificial molecules.
Physik Department E20 and ‡Institute for Advanced Study, Technische Universität München , D-85748 Garching, Germany.
Knud
K
Seufert
Willi
W
Auwärter
F J
FJ
García de Abajo
David
D
Ecija
Saranyan
S
Vijayaraghavan
Sushobhan
S
Joshi
Johannes V
JV
Barth
D004581:Electronics; D004583:Electrons; D016252:Microscopy, Scanning Tunneling; D012834:Silver / Q000737:chemistry*; D013057:Spectrum Analysis; D013499:Surface Properties
D012834:Silver