Quasicrystalline spin liquid

The interplay of electronic interactions and frustration in crystalline systems leads to a panoply of correlated phases, including exotic Mott insulators with nontrivial patterns of entanglement. Disorder introduces additional quantum interference effects that can drive localization phenomena. Quasicrystals, which are neither disordered nor perfectly crystalline, are interesting playgrounds for studying the effects of interaction, frustration, and quantum interference. Here we consider a solvable example of a quantum spin liquid on a tricoordinated quasicrystal. We extend Kitaev's original construction for the spin model to our quasicrystalline setting and perform a large-scale flux sampling to find the ground-state configuration in terms of the emergent Majorana fermions and flux excitations. This reveals a fully gapped and time-reversal-symmetric quantum spin liquid, regardless of the exchange anisotropies, accompanied by a tendency toward nontrivial (de)localization at the edge and the bulk. The advent of moir\'e materials and a variety of quantum simulators provide a new platform to bring phases of quasicrystalline quantum matter to life in a controlled fashion.