Three-colored quantum scars in the kagome quantum antiferromagnet*

Non-equilibrium properties of quantum materials present many intriguing properties, among them athermal behavior, which violates the eigenstate thermalization hypothesis. Such behavior has primarily been observed in disordered systems. More recently, experimental and theoretical evidence for athermal eigenstates, known as "quantum scars", has emerged in non-integrable disorder-free models in one dimension with constrained dynamics. In this work we investigate quantum scar eigenstates and the associated dynamical properties for the two dimensional kagome antiferromagnet. The model we study was previously shown to harbor a special exactly solvable point with three-color ground states, which involves only nearest neighbor XXZ interactions [H. J. Changlani et al. Phys. Rev. Lett. 120, 117202 (2018)]. In particular, we demonstrate the occurrence of low entanglement states spread throughout the middle of the spectrum and show quantum revivals for appropriately chosen initial states. We also present natural generalizations of our ideas to higher dimensions.