Spin-liquid signatures in the quantum critical regime of pressurized CePdAl

Abstract

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 ($\mu$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 $T\le T^{\ast }$ 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.

5 pages, 4 figures and supplemental material (3 pages, 4 figures)

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Cited by in corpus (11)

• Perspective on the muon-spin rotation/relaxation under hydrostatic pressure
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• Quantum critical spin-liquid-like behavior in S = 1/2 quasikagome lattice CeRh1-xPdxSn investigated using muon spin relaxation and neutron scattering
• Pair density wave, unconventional superconductivity, and non-Fermi liquid quantum critical phase in frustrated Kondo lattice
• Quantum spin liquid in an RKKY-coupled two-impurity Kondo system
• Frustration-induced quantum criticality in Ni-doped CePdAl as revealed by the $\mu$SR technique
• Asymmetry effects on the phases of RKKY-coupled two-impurity Kondo systems
• Magnetic dilution in the triangular lattice antiferromagnet NaYb${}_{1-x}$Lu${}_x$O${}_2$
• Microscopic evidence of a field-induced critical spin-liquid state in a frustrated metal
• Excess heat capacity in magnetically ordered Ce heavy fermion metals
• Magnetic field and pressure tuning of the heavy fermion antiferromagnet CePdIn