Abstract
Pyrochlore materials are characterized by their hallmark network of corner-sharing rare-earth tetrahedra, which can produce a wide array of complex magnetic ground states. Ferromagnetic Ising pyrochlores often obey the "two-in-two-out"spin ice rules, which can lead to a highly degenerate spin structure. Large moment systems, such as Ho2Ti2O7 and Dy2Ti2O7, tend to host a classical spin ice state with low-temperature spin freezing and emergent magnetic monopoles. Systems with smaller effective moments, such as Pr3+-based pyrochlores, have been proposed as excellent candidates for hosting a "quantum spin ice"characterized by entanglement and a slew of exotic quasiparticle excitations. However, experimental evidence for a quantum spin ice state has remained elusive. Here, we show that the low-temperature magnetic properties of Pr2Sn2O7 satisfy several important criteria for continued consideration as a quantum spin ice. We find that Pr2Sn2O7 exhibits two distinct spin-correlation time scales of τ≥10-4 and ∼10-10 s in the spin ice regime. Our comprehensive bulk characterization and neutron scattering measurements enable us to map out the magnetic field-temperature phase diagram, producing results consistent with expectations for a ferromagnetic Ising pyrochlore. We identify key hallmarks of spin ice physics and show that the application of small magnetic fields (μ0Hc∼0.5 T) suppresses the spin ice state and induces a field-polarized, ordered spin-ice phase. Together, our work clarifies the current state of Pr2Sn2O7 and encourages future studies aimed at exploring the potential for a quantum spin ice ground state in this system.
| Original language | English |
|---|---|
| Article number | 134420 |
| Journal | Physical Review B |
| Volume | 109 |
| Issue number | 13 |
| DOIs | |
| State | Published - Apr 1 2024 |
Funding
B.R.O. (synthesis, bulk properties measurements and analysis), A.F.M. (bulk properties measurements), and J.A.M.P. (inelastic neutron scattering analysis, Monte Carlo simulations), gratefully acknowledge support from the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. P.M.S. acknowledges additional financial support from the CCSF, RSC, ERC, and the University of Edinburgh through the GRS and PCDS. C.R.W. acknowledges financial support from the CRC (Tier II) program, CIFAR, CFI and NSERC. A portion of this research used resources at the High Flux Isotope Reactor, which is a DOE Office of Science User Facility operated by Oak Ridge National Laboratory. S.D.W., G.P., M.J.K., S.J.G.A., and P.M.S. acknowledge support from the U.S. Department of Energy (DOE), Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Grant No. DE-SC0017752. Neutron data collection on the Diffuse Scattering Spectrometer D7 at the ILL took place with financial support from proposal 5-42-434 awarded to P.M.S. and C.R.W. A portion of this work used facilities supported via the UC Santa Barbara NSF Quantum Foundry funded via the Q-AMASE-i program under award DMR-1906325.