Quasiparticles Andreev scattering in the ν=1/3 fractional quantum Hall regime

The scattering of exotic quasiparticles may follow different rules than electrons. In the fractional quantum Hall regime, a quantum point contact (QPC) provides a source of quasiparticles with selectable charges and statistics. These can then be scattered on a downstream ‘analyzer’ QPC to investigate these rules. Remarkably, for incident quasiparticles dissimilar to those naturally transmitted across the analyzer, electrical conduction conserves neither their nature nor their number. Indeed, theory predicts the emergence of a mechanism akin to the Andreev reflection, but without interface with a superconductor or a different quantum Hall state.

Here, thanks to shot noise and cross-correlation measurements, I will present direct observations of this predicted Andreev-like reflection of an e/3 quasiparticle into a −2e/3 hole accompanied by the transmission of a charge e quasielectron. Given the multiplicity of quasiparticles accessible through the tuning of the filling factor, it is likely that the present observation develops into a family of Andreev-like mechanisms. It may have implications toward the generation of exotic quasi-particles/holes and non-local entanglements.