Nodal superconductivity and non-Fermi-liquid behavior in Ce2PdIn8 studied by 115In nuclear quadrupole resonance

TL;DR

This study investigates Ce2PdIn8, revealing nodal superconductivity and non-Fermi-liquid behavior near an antiferromagnetic quantum critical point through nuclear quadrupole resonance measurements.

Contribution

It provides the first detailed NQR analysis of Ce2PdIn8, demonstrating its unconventional superconductivity and proximity to a quantum critical point.

Findings

Spin-lattice relaxation rate is temperature independent above 30K.

Below T_c, 1/T_1 decreases as T^3 without a coherence peak.

Evidence of line nodes in the superconducting gap.

Abstract

Nuclear quadrupole resonance measurements were performed on the heavy fermion superconductor Ce2PdIn8. Above the Kondo coherence temperature T_coh \simeq 30K, the spin-lattice relaxation rate 1/T_1 is temperature independent, whereas at lower temperatures, down to the onset of superconductivity at T_c = 0.64K, it is nearly proportional to T^{1/2}. Below T_c, 1/T_1 shows no coherence peak and decreases as T^3 down to 75mK. All these findings indicate that Ce2PdIn8 is close to the antiferromagnetic quantum critical point, and the superconducting state has an unconventional character with line nodes in the superconducting gap.