Electrical Addressing of Confined Quantum Systems for Quasiclassical Computation and Finite State Logic Machines

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 102; no. 16; pp. 5653 - 5658
• Main Authors: Remacle, F., Heath, J. R., Levine, R. D.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 19.04.2005; National Acad Sciences
• Subjects: Addition; Boolean data; Circuits; Electric current; Electric potential; Electrodes; Electron spectroscopy; Electrons; Energy; Logic; Logic circuits; Physical Sciences; Quantum theory; Resonance lines; Spectrum analysis
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.0501623102

Conduction spectroscopy measures the current I through a nanosystem as a function of the voltage V between two electrodes. The differential conductance, dI/dV, has peaks that can be assigned to resonance conditions with different electronic levels of the system. Between these increments, the current has roughly constant plateaus. We discuss how measurements of the current vs. voltage can be used to perform Boolean operations and hence construct finite state logic machines and combinational circuits. The inputs to the device are the source-drain voltage, including its sign, and a gate voltage applied in a manner analogous to optical Stark spectroscopy. As simple examples, we describe a two-state set-reset machine (a machine whose output depends on the input and also on its present state) and a full adder circuit (a circuit that requires three inputs and provides two outputs).