论文标题
加压cepdal的量子临界状态中的自旋液体特征
Spin-liquid signatures in the quantum critical regime of pressurized CePdAl
论文作者
论文摘要
CePdAl is a prototypical frustrated Kondo lattice with partial long-range order (LRO) at $T_\mathrm{N}=2.7$ K. Previous bulk experiments under hydrostatic pressure found signatures for a quantum critical regime that extends from $p_\mathrm{c} \approx 0.9$ GPa, where LRO disappears, up to $\sim 1.7$ GPa.我们在压力下采用了广泛的MUON自旋松弛和旋转（$ $ $ SR）实验。确认了$ p_ \ mathrm {c} $的LRO的连续和完全抑制。以上$ t_ \ mathrm {n}（p）$以及$ p_ \ mathrm {c} $以上，一个附加的交叉刻度$ t^\ ast（p）$表征了从纯度到零字段中纯指数放松的变化。明显的$ t^\ ast（p）$与先前确定的熵积累的签名一致。在$ t \ leq t^\ ast $上，这种巧合的显着性证据与自旋 - 液体行为波动。在$ p_c $和1.7 GPA之间的压力下，温度和纵向场的幂律差异将这种制度定义为量子关键。
CePdAl is a prototypical frustrated Kondo lattice with partial long-range order (LRO) at $T_\mathrm{N}=2.7$ K. Previous bulk experiments under hydrostatic pressure found signatures for a quantum critical regime that extends from $p_\mathrm{c} \approx 0.9$ GPa, where LRO disappears, up to $\sim 1.7$ GPa. We employed extensive muon spin relaxation and rotation ($μ$SR) experiments under pressure. The continuous and complete suppression of LRO at $p_\mathrm{c}$ is confirmed. Above $T_\mathrm{N}(p)$ and beyond $p_\mathrm{c}$, an additional crossover scale $T^\ast(p)$ characterizes the change from pure to stretched exponential relaxation in zero field. Remarkably $T^\ast(p)$ agrees with previously determined signatures of entropy accumulation above LRO. This coincidence microscopically evidences fluctuating frustrated spins at $T\leq T^\ast$ with spin-liquid behavior. Power-law divergences of the temperature and longitudinal field dependences of the relaxation rate, with time-field scaling, at pressures between $p_c$ and 1.7 GPa characterize this regime as quantum critical.
