Disorder-induced proximate quantum spin ice phase in Pr2Sn2O7

Abstract

Magnetic pyrochlores with non-Kramers rare-earth ions provide a platform for exploring emergent gauge physics and quantum spin-ice behavior, yet the influence of structural disorder on their ground states remains insufficiently understood. Here we combine bulk characterization and single-crystal neutron-scattering measurements to investigate the non-Kramers pyrochlore Pr2Sn2O7. At temperatures below ~1 K, the system exhibits key hallmarks of quantum spin-ice physics, including anisotropic spin-ice correlations and two distinct dynamical timescales. Upon further cooling, however, we observe a complete spin-freezing transition at T_f ~ 0.15 K, accompanied by recovery of the full nuclear Schottky anomaly, the emergence of a gapped magnetic excitation, and the development of incipient (100) magnetic correlations. Comparison with related Pr-based pyrochlores places Pr2Sn2O7 near the spin-frozen boundary of a disorder-perturbed phase diagram. These results establish a disorder-driven framework for the evolution of quantum spin-ice behavior into frozen ground states, revealing how signatures of a proximate quantum spin liquid can persist despite disorder-induced spin freezing in non-Kramers pyrochlores.

14 pages, 5 figures, and 1 table in the main text; 12 pages, 11 figures, and 1 table in the Supplementary Information. v5 (08/05/2026): The published version. v4(05/25/2026): Updated Fig. S2. v3 (05/07/2025): Revised the Introduction and Discussion sections and added a comparative analysis of multiple Pr-based pyrochlores. v2 (09/16/2025): Corrected typographical errors and DOIs in the references