115In NQR study with evidence for two magnetic quantum critical points in dual Ce site superconductor Ce3PtIn11

Authors: Kambe, H. Sakai, Y. Tokunaga, R.E. Walstedt, M. Kratochvílová, K. Uhlířová, J. Custers

Phys. Rev. B 101 (2020) 081103(R).

Abstract:  $115\mathrm{In}$ nuclear quadrupole resonance (NQR) measurements have been carried out on ${\mathrm{Ce}}_3{\mathrm{PtIn}}_{11}$, a heavy fermion compound harboring two inequivalent Ce sites. This system exhibits magnetic transitions at $T_{1n}=2.2$ K and $T_N=2$ K, prior to entering a superconducting state below $T_{\text{c}}=0.32$ K. Previous measurements imply that magnetism and superconductivity are spatially separated and only the Ce(2) sublattice orders magnetically, with a quantum critical point at pressure $p_c=1.3$ GPa, while the Ce(1) sublattice is paramagnetic. However, the present nuclear relaxation rate behavior of $1/T_1\propto \sqrt{T}$ reveals the presence of critical spin fluctuations indicative of close proximity to another quantum critical point, presumably at a small negative pressure, which is associated solely with the Ce(1) sublattice. The ordered wave vector is found to be most likely $(1/2,1/2,h)$.

DOI: https://doi.org/10.1103/PhysRevB.101.081103