



01383nas a2200157   4500008004100000245005600041210005500097260001400152490000800166520093200174100002001106700001601126700002501142700002101167856003701188       2020                        eng d00aHilbert-Space Fragmentation from Strict Confinement0 aHilbertSpace Fragmentation from Strict Confinement  c5/22/20200 v1243 a<p>We study one-dimensional spin-1/2 models in which strict confinement of Ising domain walls leads to the fragmentation of Hilbert space into exponentially many disconnected subspaces. Whereas most of the previous works emphasize dipole moment conservation as an essential ingredient for such fragmentation, we instead require two commuting U(1) conserved quantities associated with the total domain-wall number and the total magnetization. The latter arises naturally from the confinement of domain walls. Remarkably, while some connected components of the Hilbert space thermalize, others are integrable by Bethe ansatz. We further demonstrate how this Hilbert-space fragmentation pattern arises perturbatively in the confining limit of Z2 gauge theory coupled to fermionic matter, leading to a hierarchy of time scales for motion of the fermions. This model can be realized experimentally in two complementary settings.</p>1 aYang, Zhi-Cheng1 aLiu, Fangli1 aGorshkov, Alexey, V.1 aIadecola, Thomas  uhttps://arxiv.org/abs/1912.04300