2008/07/03 by Muhammad Haider, Haider, M. Baseer, Jason Pitters +9 · 2 citations
Computer Science · Physics and Astronomy · #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Other Condensed Matter (cond-mat.other) #Quantum and electron transport phenomena #Quantum-Dot Cellular Automata #Semiconductor Quantum Structures and Devices
paper · pdf · doi:10.48550/arxiv.0807.0609
openalex publication_date 2008/07/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
It is discovered that the zero-dimensional character of the silicon atom dangling bond (DB) state allows controlled formation and occupation of a new form of quantum dot assemblies. Whereas on highly doped n-type substrates isolated DBs are negatively charged, it is found that Coulomb repulsion causes DBs separated by less than ~2 nm to experience reduced localized charge. The unoccupied states so created allow a previously unobserved electron tunnel-coupling of DBs, evidenced by a pronounced change in the time-averaged view recorded by scanning tunneling microscopy. Direct control over net electron occupation and tunnel-coupling of multi-DB ensembles through separation controlled is demonstrated. Through electrostatic control, it is shown that a pair of tunnel-coupled DBs can be switched from a symmetric bi-stable state to one exhibiting an asymmetric electron occupation. Similarly, the setting of an antipodal state in a square assembly of four DBs is achieved, demonstrating at room temperature the essential building block of a quantum cellular automata device.