Controlled coupling and occupation of silicon atomic quantum dots at room temperature

It is demonstrated that the silicon atom dangling bond (DB) state serves as a quantum dot. Coulomb repulsion causes DBs separated by □ 2nm to exhibit reduced localized charge, which enables electron tunnel coupling of DBs. Scanning tunneling microscopy measurements and theoretical modeling reveal that fabrication geometry of multi-DB assemblies determines net occupation and tunnel coupling strength among dots. Electron occupation of DB assemblies can be controlled at room temperature. Electrostatic control over charge distribution within assemblies is demonstrated.