Supersolid devil's staircases of spin-orbit-coupled bosons in optical lattices

Abstract

We study the emergence of supersolid devil's staircases of spin-orbit-coupled bosons loaded in optical lattices. We consider two- and three-dimensional systems of pseudo-spin-1/2 bosons interacting via local spin-dependent interactions. These interactions together with spin-orbit coupling produce length scales that are commensurate to the lattice spacing. This commensurability leads to devil's staircases of supersolids, with fractal Hausdorff dimensions, which arise from uniform superfluid phases. We show that umklapp processes are essential for the existence of commensurate supersolids, and that without them the devil's staircase does not exist. Lastly, we emphasize the generality of our results, suggest experiments that can unveil these unusual predictions, and discuss potential applications to the case of Rb87.Received 14 January 2022Revised 10 May 2022Accepted 12 July 2022DOI:https://doi.org/10.1103/PhysRevResearch.4.L032023Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasCold gases in optical latticesPhysical SystemsBose gasesSupersolidsAtomic, Molecular & Optical