In a frustrated quantum magnet, competing interactions among neighboring electronic spins prevent the system from settling into an ordered ground state near absolute zero temperature—giving rise to an exotic state known as a quantum spin liquid. The leading model for studying 3D frustrated quantum magnets is the Heisenberg model on the pyrochlore lattice. And yet, theoretical analysis of this model is plagued with serious difficulties. Here, we develop a more complete picture of this model by tackling some of these difficulties.

We employ a state-of-the-art methodological framework to explore the effects of quantum fluctuations on the Heisenberg pyrochlore model, a notoriously difficult problem that had not yet been adequately addressed. Our approach allows us to study the onset of these fluctuations as one tunes the length of the spins in the model from infinite down to their lowest permissible value of one-half. The length of the spin thus serves as a knob that can be used to tune the “quantumness” in the system, which is maximal for a length of one-half. Following this procedure, we reveal the presence of extended regions of quantum-spin-liquid behavior.

Our analysis provides a platform to develop a deeper theoretical understanding of pyrochlore magnets, and thus aspires to catalyze the search for 3D spin liquids in quantum materials.