Two‐particle interferometry in quantum Hall edge channels

Since the pioneering works of Hanbury‐Brown and Twiss, intensity–intensity correlations have been widely used in astronomical systems, for example, to detect binary stars. They reveal statistics effects and two‐particle interference, and offer a decoherence‐free probe of the coherence properties of light sources. In the quantum Hall edge channels, the concept of quantum optics can be transposed to electrons, and an analogous two‐particle interferometry can be developed, in order to characterize single‐electron states. We review in this article the recent experimental and theoretical progress on this topic. Two‐photon interferometry has been widely used in astronomical systems since the late 1950s, for example to detect binary stars. In quantum Hall edge channels, this concept can be transposed to electrons propagating in electron quantum optics devices. Two‐particle interferometry then reveals statistics effects and provides means to characterize an electronic quantum state. In this Feature Article, the recent experimental and theoretical progress in the field is reviewed.