Many-body flatband localization

We generate translationally invariant systems exhibiting many-body localization from all-bands-flat single-particle lattice Hamiltonians dressed with suitable short-range many-body interactions. This many-body flatband localization is based on symmetries of both single-particle and interaction terms in the Hamiltonian, and it holds for any interaction strength. We propose a generator of corresponding Hamiltonians which covers both interacting bosons and fermions for arbitrary lattice dimensions, and we provide explicit examples of such models in one and two lattice dimensions. We also explicitly construct an extensive set of local integrals of motion for this set of models.

Suitable short-range many-body interactions result in complete suppression of only  charge transport due to Many-Body Flatband Localization. We show that heat transport is forbidden in dimension one. In higher dimensions heat transport can be unlocked by tuning filling fractions across a percolation transition for suitable lattice geometries.

When adding dispersive degrees of freedom, the locaked flatband charges act as scatterers due to the nonzero interaction. We then obtain an MBL transition upon varying the strength of interaction in such a mixed system.