标题： 无序诱导的临近量子自旋冰相在Pr$_2$Sn$_2$O$_7$ 显示英文标题

标题： Disorder-induced proximate quantum spin ice phase in Pr$_2$Sn$_2$O$_7$

摘要： 我们报告了对单晶Pr$_2$Sn$_2$O$_7$的全面体材料表征和中子散射研究，这是一种通过助熔剂生长方法合成的磁性pyrochlore。 未极化的中子漫散射显示，在$T \sim 1$ K以下出现了自旋冰相关性，这由各向异性的捏点特征的发展所证实，这些特征与量子自旋冰（QSI）行为一致。 A.C.磁化率测量表明，在这个区域中自旋动力学逐渐变慢，最终在低于$T_f \approx 0.15$K 时完全自旋冻结。在$T = 0.5$K 时的非弹性中子散射显示，存在一个宽广的准弹性磁激发谱，在低能范围$[0, 0.2]$meV 的强度显著低于$T_f$。同时，(100)型磁序开始萌芽，一个在$\hbar\omega = 0.23$meV 处的有隙激发仍然存在。 我们在$T_f$以上进一步识别出两个不同的动力学时间尺度，一个缓慢分量$\tau_{\mathrm{slow}} \sim 10^{-5}$ s 和一个快速分量$\tau_{\mathrm{fast}} \sim 10^{-10}$ s，与 QSI 系统的理论预测定量一致。 这些结果共同表明，Pr$_2$Sn$_2$O$_7$在低于$T_f$时进入无序诱导的自旋冻结相，靠近一个$U(1)$量子自旋液体。 显示英文摘要

摘要： We report a comprehensive bulk characterization and neutron scattering investigation of single-crystalline Pr$_2$Sn$_2$O$_7$, a magnetic pyrochlore synthesized via a flux-growth method. Unpolarized neutron diffuse scattering reveals the emergence of spin-ice correlations below $T \sim 1$ K, evidenced by the development of anisotropic pinch-point features that are consistent with quantum-spin-ice (QSI) behavior. A.C. susceptibility measurements indicate a progressive slowing of spin dynamics in this regime, culminating in complete spin freezing below $T_f \approx 0.15$ K. Inelastic neutron scattering at $T = 0.5$ K reveals a broad spectrum of quasi-elastic magnetic excitations, with intensity in the low-energy range $[0, 0.2]$ meV significantly suppressed below $T_f$. Meanwhile, an incipient (100)-type magnetic order begins to nucleate, and a gapped excitation centered at $\hbar\omega = 0.23$ meV persists. We further identify two distinct dynamical timescales above $T_f$, a slow component $\tau_{\mathrm{slow}} \sim 10^{-5}$ s and a fast component $\tau_{\mathrm{fast}} \sim 10^{-10}$ s, in quantitative agreement with theoretical predictions for QSI systems. Taken together, these results indicate that Pr$_2$Sn$_2$O$_7$ enters a disorder-induced spin-frozen phase below $T_f$, lying in close proximity to a $U(1)$ quantum spin liquid.