Active Nanoelectronic Devices and Circuits
Árpád I. Csurgay, György Csaba, Wolfgang Porod · 2001
Three ways of nanodevice interconnection have beensuggested so far. Metal-contacted devices in the meso-scalerange (10 to 100 nanometer), such as nano-transistors,resonant tunneling devices, RTDs and metal-dot singleelectron transistors, SETs, can be interconnected with wires.As long as each device has metal contacts, i.e. they are allembedded into ‘heat baths’, conventional interconnectionwith wires is possible. In this case circuit dynamicsfollowing the conservation laws of charge and energy obeysKirchhoff’s laws. However, nanodevices not metalcontacted, e.g. quantum-dot arrays and artificial atoms andmolecules can be coupled by inter-device electron transportor by electromagnetic fields. In case of wiring and inter-device electron transport the current flow generatesunavoidable dissipation. An alternative approach of deviceintegration is electromagnetic field interaction between thedevices, such as coupling by Coulomb- or by magneticforces. This approach can bring devices closer to each otherand significantly decrease dissipation.Field-coupled nanoelectronic discrete devices andsimple circuits, such as wires, switches and logic gates,based on quantum phenomena have been demonstrated.However, there has been no viable design procedures forlarge-scale integration proposed.If both field-coupled and metal-contacted nanodevicesare applied in the same circuit, the physical interfacebetween a field-coupled and a metal-contacted nanodevicecan be represented as a classical electromagnetic circuit. Theboundary conditions on the side of the metal contacteddevice are defined by the metal contacts, on the side of thefield-coupled device by the electric or magnetic field ofgenerated by the nanodevices.In reference [1] we concluded that integrated circuitscomposed of field-coupled and metal-contacted nanodevicesdo have equivalent circuit representations, thus circuit theorytechniques can be applied to build device models, tosimulate and to aid the design of large-scale nanoelectronicintegrated circuits.Circuit models of nanodevices having electronic andmechanic (nuclear or phonic) degrees of freedom werepresented. An approximate model of individual isolateddevices (molecules), models for structures with weakcoupling between nanodevice neighbors; models of thethermal bath and damping channels, and models for theexternal forces were presented (Figure 1).