It is common to differentiate between two ways of building a nanodevice: a top-down approach where we start from something big and chisel out what we want and a bottom-up approach where we start from something small like atoms or molecules and assemble what we want. When it comes to describing electrical resistance, the standard approach could be called a "top-down" one that starts from large conductors and works its way down. In this talk I will present a different view of electrical conduction, one that could be called a bottom-up viewpoint. I use this viewpoint to introduce listeners to the non-equilibrium Green's function (NEGF) method widely used to simulate all kinds of nanoscale devices from small molecules to carbon nanotubes to silicon nanotransistors.
Purdue University, West Lafayette, IN