Particles Network Device
Dr. Nadjib Baadji, CRANN, School of Physics, Trinity College Dublin
Particles networks are an interesting technological platform for the construction of novel logic devices, in particular for devices using alternative strategies then Boolean logic. The concept is that of having metallic nanoparticles (typically with a diameter in the 20 nano-meters range) connected with each other through molecular bridges. Ideally one would wish to use bridging molecules that can switch, so that the entire network can be reconfigured and interrogated by external stimuli. Also important is the ability to understand the response of the network when closely adjacent nodes are individually interrogated.
The simulations of these networks is rather complex since it requires an accurate description at the junction level (i.e. a description of the electrical transport through molecules attached to the nano-particles), but also the ability of simulating the entire network electrical response. We model the single junctions via accurate electron transport theory combined with density functional methods, a scheme that is presently coded in the Dublin based Smeagol package (www.smeagol.tcd.ie). As for the network we have recently developed a Green's function based scheme for evaluating I-V characteristics under various bias conditions.
Critical to the analysis and the diagnostic of the networks is the ability to visualize preferential current paths, potential drop and critical breaking points for the network functionality. In collaboration with TCHPC we have developed a fully user friendly visualization suit that allows us to study those aspects of the network, as well as allowing us to compare different networks and different regions of the same one.