Quantum nanoelectronics has entered an era where quantum electrical currents are built from single to few elementary excitations generated on demand. To characterize them and analyze their fast dynamics, one needs to develop new experimental tools. For instance, the electronic Hong Ou Mandel interferometer enables to characterize such signals. It relies on the single particle overlap of the two inputs i.e. it is a two-particle interferometer.
I will first briefly present how we used this two-particle interferometer to probe the decoherence and relaxation of a propagating single electron. Then I will present how we used this two-particle interference as a quantum current analyzer able to extract single particle excitations present within a periodic quantum electrical current without any a priori hypothesis. Combined with signal processing we extract the relevant electron and hole wavefunctions localized around each emission period and their quantum coherence from one emission period to the other.