Hilbert space fragmentation in a 2D quantum spin system with subsystem symmetries
Alexey Khudorozhkov, Apoorv Tiwari, Claudio Chamon, Titus Neupert
SciPost Phys. 13, 098 (2022) · published 19 October 2022
- doi: 10.21468/SciPostPhys.13.4.098
- Submissions/Reports
Abstract
We consider a 2D quantum spin model with ring-exchange interaction that has subsystem symmetries associated to conserved magnetization along rows and columns of a square lattice, which implies the conservation of the global dipole moment. In a certain regime, the model is non-integrable, but violates the eigenstate thermalization hypothesis through an extensive Hilbert space fragmentation, including an exponential number of inert subsectors with trivial dynamics, arising from kinetic constraints. While subsystem symmetries are quite restrictive for the dynamics, we show that they alone cannot account for such a number of inert states, even with infinite-range interactions. We present a procedure for constructing shielding structures that can separate and disentangle dynamically active regions from each other. Notably, subsystem symmetries allow the thickness of the shields to be dependent only on the interaction range rather than on the size of the active regions, unlike in the case of generic dipole-conserving systems.
Cited by 19
Authors / Affiliations: mappings to Contributors and Organizations
See all Organizations.- 1 2 Alexey Khudorozhkov,
- 3 4 Apoorv Tiwari,
- 2 Claudio Chamon,
- 4 Titus Neupert
- 1 Eidgenössische Technische Hochschule Zürich / Swiss Federal Institute of Technology in Zurich (ETH) [ETH Zurich]
- 2 Boston University [BU]
- 3 Paul Scherrer Institute [PSI]
- 4 Universität Zürich / University of Zurich [UZH]
- Horizon 2020 (through Organization: European Commission [EC])
- United States Department of Energy [DOE]