Realization of fractonic quantum phases in the breathing pyrochlore lattice

Fractonic phases of matter are characterized as possessing unusual mobility restricted quasiparticle excitations, and a ground state degeneracy that is sub-extensive and geometry dependent. While there exist a number of exactly solvable models with interactions between multiple particles/spins, the realization of such models in real materials is extremely challenging. In this talk, we investigate a realistic novel fractonic phase of matter that arises from a quantum model of quadratic spin interaction on the breathing pyrochlore lattice. Using membrane operators, we demonstrate the existence of a sub-extensive ground state degeneracy explicitly depending on the lattice geometry. This work provides a natural and realistic scenario to realize such exotic phases of matter, and a promising foundation for future theoretical and experimental investigations. [arXiv:2109.03835]