Scar states in a system of interacting chiral fermions

In generic quantum many-body systems, the exact eigenstates are expected to satisfy the eigenstate thermalization hypothesis: Eigenstates near any given energy are expected to be thermodynamically equivalent. The authors demonstrate that in a system of chiral fermions with generic interaction this expectation is violated by some states. They find a coexistence of fermionic and bosonic types of eigenstates in some regions of the many-body spectrum. This allows for observable density oscillations even at weak coupling.