%0 Journal Article %1 PhysRevLett.125.240401 %A Srivatsa, N. S. %A Moessner, Roderich %A Nielsen, Anne E. B. %D 2020 %I American Physical Society %J Phys. Rev. Lett. %K a %N 24 %P 240401 %R 10.1103/PhysRevLett.125.240401 %T Many-body delocalization via emergent symmetry %U https://link.aps.org/doi/10.1103/PhysRevLett.125.240401 %V 125 %X Many-body localization (MBL) provides a mechanism to avoid thermalization in many-body quantum systems. Here, we show that an emergent symmetry can protect a state from MBL. Specifically, we propose a $Z_2$ symmetric model with nonlocal interactions, which has an analytically known, SU(2) invariant, critical ground state. At large disorder strength all states at finite energy density are in a glassy MBL phase, while the lowest energy states are not. These do, however, localize when a perturbation destroys the emergent SU(2) symmetry. The model also provides an example of MBL in the presence of nonlocal, disordered interactions that are more structured than a power law. The presented ideas raise the possibility of an `inverted quantum scar', in which a state that does not exhibit area law entanglement is embedded in an MBL spectrum, which does.

@article{PhysRevLett.125.240401, abstract = {Many-body localization (MBL) provides a mechanism to avoid thermalization in many-body quantum systems. Here, we show that an emergent symmetry can protect a state from MBL. Specifically, we propose a $Z_2$ symmetric model with nonlocal interactions, which has an analytically known, SU(2) invariant, critical ground state. At large disorder strength all states at finite energy density are in a glassy MBL phase, while the lowest energy states are not. These do, however, localize when a perturbation destroys the emergent SU(2) symmetry. The model also provides an example of MBL in the presence of nonlocal, disordered interactions that are more structured than a power law. The presented ideas raise the possibility of an `inverted quantum scar', in which a state that does not exhibit area law entanglement is embedded in an MBL spectrum, which does.}, added-at = {2020-12-28T17:16:34.000+0100}, author = {Srivatsa, N. S. and Moessner, Roderich and Nielsen, Anne E. B.}, biburl = {https://www.bibsonomy.org/bibtex/26ac010e5878712bf8e2961754357aa11/ctqmat}, day = 8, description = {Phys. Rev. Lett. 125, 240401 (2020) - Many-Body Delocalization via Emergent Symmetry}, doi = {10.1103/PhysRevLett.125.240401}, interhash = {58a3235f46a51d460ed3a94fd211c210}, intrahash = {6ac010e5878712bf8e2961754357aa11}, journal = {Phys. Rev. Lett.}, keywords = {a}, month = {12}, number = 24, numpages = {5}, pages = 240401, publisher = {American Physical Society}, timestamp = {2023-10-13T12:51:45.000+0200}, title = {Many-body delocalization via emergent symmetry}, url = {https://link.aps.org/doi/10.1103/PhysRevLett.125.240401}, volume = 125, year = 2020 }