2019/06/30 by Michael Schecter, Thomas Iadecola · 5 citations
Mathematics · Physics and Astronomy · #Eigenvalues and eigenvectors #Ergodic theory #Ergodicity #Hamiltonian (control theory) #Mathematics #Observable #Physics #Physics of Superconductivity and Magnetism #Pure mathematics #Quantum #Quantum and electron transport phenomena #Quantum entanglement #Quantum many-body systems #Quantum mechanics #Statistical physics #Theoretical physics #Thermalisation #cond-mat.stat-mech #cond-mat.str-el #quant-ph
paper · pdf · doi:10.1103/physrevlett.123.147201
published as Phys. Rev. Lett. 123, 147201 (2019) · 5+(10+epsilon) pages, 4 figures; v2 adds two new appendices discussing connections to embedded Hamiltonians and generalizations to spin-S models
arxiv created 2019/07/01 · openalex created_date 2019/07/12 · openalex publication_date 2019/10/01 · arxiv updated 2019/10/03 · openalex updated_date 2026/08/05
We study the spin-1 XY model on a hypercubic lattice in d dimensions and show that this well-known nonintegrable model hosts an extensive set of anomalous finite-energy-density eigenstates with remarkable properties. Namely, they exhibit subextensive entanglement entropy and spatiotemporal long-range order, both believed to be impossible in typical highly excited eigenstates of nonintegrable quantum many-body systems. While generic initial states are expected to thermalize, we show analytically that the eigenstates we construct lead to weak ergodicity breaking in the form of persistent oscillations of local observables following certain quantum quenches-in other words, these eigenstates provide an archetypal example of so-called quantum many-body scars. This Letter opens the door to the analytical study of the microscopic origin, dynamical signatures, and stability of such phenomena.