Interconnected ultrathin conducting wires or, equivalently, interconnected quasi-one-dimensional electron waveguides, which form a quantum resistor network, are presented here in four-terminal configurations. The transmission behaviors through such four-terminal networks are evaluated and classified. In addition, we show that such networks can be used as the basic building blocks for a possible massive wave computing machine in the future. In a network, each interconnection, a node point, is an elastic scatterer that routes the electron wave. Routing and rerouting of electron waves in a network is described in the framework of quantum transport from Landauer-Buttiker theory in the presence of multiple elastic scatterers. Transmissions through various types of four-terminal generalized clean Aharonov-Bohm rings are investigated at zero temperature. Useful logic functions are gathered based on the transmission probability to each terminal with the use of the Buttiker symmetry rule. In the generalized rings, even and odd numbers of terminals can possess some distinctly different transmission characteristics as we have shown here and earlier. Just as an even or odd number of atoms in a ring is an important quantity for classifying the transmission behavior, we show here that whether the number of terminals is an even or an odd number is just as important in understanding the physics of transmission through such a ring. Furthermore, we show that there are three basic classes of four-terminal rings and the scaling relation for each class is provided. In particular, the existence of equitransmission among all four terminals is shown here. This particular physical phenomena cannot exist in any three-terminal ring. Comparisons and discussions of transmission characteristics between three-terminal and four-terminal rings are also presented. The node-equation approach by considering the Kirchhoff current conservation law at each node point is used for this analysis. Many useful logic functions for electron-wave computing are shown here. In particular, we show that a full adder can be constructed very simply using the equitransmission property of the four-terminal ring. This is in sharp contrast with circuits based on transistor logic.
D. Ramamurthy and C. Wu, "Four-Terminal Quantum Resistor Network for Electron-Wave Computing," Physical Review B - Condensed Matter and Materials Physics, vol. 66, no. 11, American Physical Society (APS), Sep 2002.
The definitive version is available at http://dx.doi.org/10.1103/PhysRevB.66.115307
Electrical and Computer Engineering
Keywords and Phrases
Article; Electric Current; Electron Transport; Electronics; Machine; Semiconductor; Temperature Dependence
International Standard Serial Number (ISSN)
Article - Journal
© 2002 American Physical Society (APS), All rights reserved.