Speaker
Description
Quantum many-body scar (QMBS) states, which are special energy eigenstates that violate the eigenstate thermalization hypothesis in nonintegrable systems, have attracted much attention. Recently, asymptotic quantum many-body scar (AQMBS) states, which are closely related to QMBS states, have been proposed [1]. AQMBS states exhibit nonergodic behavior because their energy variance vanishes in the thermodynamic limit. Moreover, AQMBS states are related to Nambu-Goldstone modes, indicating a connection between thermalization in isolated quantum systems and spontaneous symmetry breaking [2]. However, existing constructions of AQMBS states are heuristic, and a systematic method for constructing them has not yet been established. In this work, we propose a systematic framework for constructing AQMBS states [3]. Within this framework, we assume a restricted spectrum-generating algebra [4,5], a symmetry-based formalism [6], and a specific structure of the Hamiltonian. Under these assumptions, AQMBS states arise as low-energy gapless excitations of a parent Hamiltonian whose ground states are QMBS states. Furthermore, we find that the algebraic relations of N=2 supersymmetric quantum mechanics naturally emerge in systems satisfying these assumptions. In this seminar, I will present the details of the method and its applications to several models.
[1]L. Gotta et al, Phys. Rev. Lett. 131, 190401 (2023).
[2]J. Ren et al., Phys. Rev. B 110, 245101 (2024).
[3]MK, Y. Kato, and H. Katsura, Phys. Rev. Res. 7, 043107 (2025).
[4]D. K. Mark et al, Phys. Rev. B 101, 195131 (2020).
[5]S. Moudgalya et al, Phys. Rev. B 102, 085140 (2020).
[6]N. O'Dea et al, Phys. Rev. Res. 2, 043305 (2020).