title: A tight-binding study of single-atom transistors.
abstract: A detailed theoretical study of the electronic and transport properties of a single atom transistor, where a single phosphorus atom is embedded within a single crystal transistor architecture, is presented. Using a recently reported deterministic single-atom transistor as a reference, the electronic structure of the device is represented atomistically with a tight-binding model, and the channel modulation is simulated self-consistently with a Thomas-Fermi method. The multi-scale modeling approach used allows confirmation of the charging energy of the one-electron donor charge state and explains how the electrostatic environments of the device electrodes affects the donor confinement potential and hence extent in gate voltage of the two-electron charge state. Importantly, whilst devices are relatively insensitive to dopant ordering in the highly doped leads, a ∼1% variation of the charging energy is observed when a dopant is moved just one lattice spacing within the device. The multi-scale modeling method presented here lays a strong foundation for the understanding of single-atom device structures: essential for both classical and quantum information processing.
authors.affiliation: National Institute of Supercomputing and Networking, Korea Institute of Science and Technology Information, Daejeon, 305-806, Republic of Korea; Network for Computational Nanotechnology, Purdue University, Indiana, 47907, USA.
authors.forename: Hoon
authors.initials: H
authors.lastname: Ryu
authors.forename: Sunhee
authors.initials: S
authors.lastname: Lee
authors.forename: Martin
authors.initials: M
authors.lastname: Fuechsle
authors.forename: Jill A
authors.initials: JA
authors.lastname: Miwa
authors.forename: Suddhasatta
authors.initials: S
authors.lastname: Mahapatra
authors.forename: Lloyd C L
authors.initials: LC
authors.lastname: Hollenberg
authors.forename: Michelle Y
authors.initials: MY
authors.lastname: Simmons
authors.forename: Gerhard
authors.initials: G
authors.lastname: Klimeck
keywords: Coulomb blockade; Si:P systems; Stark effects; atomistic modeling; single-atom transistors