Agenda

Résumé : It has been observed that isolated quantum systems often still produce measured values consistent with thermalization. This is unexpected due to the lack of a notion of chaos or ergodicity and the unitary dynamics of the quantum theory which is at its core linear. The conditions under which we can expect isolated quantum systems to thermalize were laid out in the eigenstate thermalization hypothesis (ETH), which has generally been found to hold in a variety of systems. Still, notable violations of the ETH have been identified where a seemingly chaotic many-body quantum system exhibits some nonthermal behavior. In this talk, I will introduce the concept of quantum many-body scars (QMBS), a phenomenon in which a small subset of eigenstates violates the ETH and promote nonthermal dynamics. I will then present theoretical results on a bosonic Hamiltonian with a density-dependent hopping and describe two distinct mechanisms for scar formation that arise in this model. These mechanisms provide insight into the conditions under which QMBS can be expected to occur.