In the presence of strong correlations, the electronic matter can become very different from a bath of Fermi quasiparticles. The challenge is often to reveal unambiguously the most striking characteristics, as recently illustrated by the Majorana observation controversy. The broad aim of this experimental internship/PhD is to engineer such states in electronic quantum circuits, by design, and to reveal their nature through a combination of observables, notably including their entropy contribution. The latter is particularly revealing of emerging non-abelian states, with a contribution to the ground-state entropy that can take a remarkable fractional value, between 0 and kB ln(2) (kB ln(2)/2 for a Majorana). A major objective of this project is to pinpoint the fractional entropy associated with such exotic states.