  The analog of two seminal quantum optics experiments are considered in a
condensed matter setting with single electron sources injecting electronic wave
packets on edge states coupled through a quantum point contact. When only one
electron is injected, the measurement of noise correlations at the output of
the quantum point contact corresponds to the Hanbury-Brown and Twiss setup.
When two electrons are injected on opposite edges, the equivalent of the
Hong-Ou-Mandel collision is achieved, exhibiting a dip as in the coincidence
measurements of quantum optics. The Landauer-Buttiker scattering theory is used
to first review these phenomena in the integer quantum Hall effect, next, to
focus on two more exotic systems: edge states of two dimensional topological
insulators, where new physics emerges from time reversal symmetry and three
electron collisions can be achieved; and edges states of a hybrid
Hall/superconducting device, which allow to perform electron quantum optics
experiments with Bogoliubov quasiparticles.
