Quantum electron optics and its applications

We present two recent experiments that use current fluctuation measurements to probe the second-order electron correlation function (fourth-order in wavefunction amplitude): an intensity interferometry experiment called the Hanbury Brown and Twiss (1956) experiment, and an electron collision experiment. Finally, we discuss how these two experiments can be used to characterize the unique behavior of Bell's state entangled electrons in a proposed electron bunching experiment. Throughout the paper, we consider only ballistic systems, in which the inelastic phonon scattering and the elastic ionized impurity scattering lengths axe much longer than the characteristic size of the system at cryogenic temperatures (typically 1.5 K in our experiments). The screening length (typically λsc≈5 nm) is assumed to be much smaller than the Fermi wavelength (typically λF≈40 mn) so that Coulomb interactions can be neglected. We assume ideal thermal reservoirs, independent transport channels, and transmission probabilities independent of the applied bias voltage. This approach directly follows the coherent scattering formalism