Mason Group

As device dimensions shrink down to sizes as small as tens or hundreds of nanometers, electrons are increasingly forced to interact with each other, which ultimately determines the type of quantum state that dictates how electrons move through the system. Systems that geometrically constrain where electrons may move (e.g. carbon nanotubes or nanowires) are excellent potential platforms for observing the exotic physics that may arise from electron-electron interactions.

One outstanding question that can be applied to systems with electron-electron interactions is the nature of the non-equilibrium distribution function. A technique known as non-equilibrium tunneling spectroscopy may be used to determine how exactly electrons move through a device and quantities such as energy relaxation times of quasiparticles in the system. Specifically, the distribution function f(E) may be found by measuring the conductance from a device that is coupled to a superconducting tunnel probe (with physics very similar to scanning tunneling microscopy).

This technique has been applied to carbon nanotubes and is currently being applied to InSb nanowires.