Speaker
Description
The eigenstate thermalization hypothesis (ETH) provides a theoretical framework for understanding how isolated quantum many-body systems reach thermal equilibrium. Recent experimental and theoretical studies have shown, however, that certain non-integrable systems can host atypical eigenstates that evade thermalization. These special states are called quantum many-body scars (QMBS), offering concrete examples of strong ETH violation.
In this talk, I will first give a pedagogical review of the algebraic methods used to construct such scar states. While obtaining exact eigenstates is usually restricted to integrable models, I will show how a tower of QMBS can be built in non-integrable systems by the repeated action of some judiciously chosen operator on a simple parent state.
I will then present our recent results based on integrability techniques such as integrable boundary states. These techniques allow us to construct a variety of models hosting exact QMBS in both one and higher dimensions. Time permitting, I will briefly touch on how crosscap states can be used to construct exact volume-law entangled eigenstates in non-integrable models.
[1] Kazuyuki Sanada, Yuan Miao, and Hosho Katsura, Phys. Rev. B 108, 155102 (2023).
[2] Kazuyuki Sanada, Yuan Miao, Hosho Katsura, arXiv:2411.01270.