Variation in Superconducting Symmetry with Pressure on a Noncentrosymmetric Superconductor

We performed 185/187Re nuclear quadrupole resonance (NQR) measurements under pressure to investigate the superconducting properties of noncentrosymmetric superconductor Cd2Re2O7 under various crystal structures. The pressure dependence of superconducting transition temperature Tc determined through ac susceptibility measurements is consistent with the results of previous resistivity measurements [Kobayashi et al., J. Phys. Soc. Jpn. 80, 023715 (2011)]. Below 2.2 GPa, in the nuclear spin–lattice relaxation rate 1/T1, a clear coherence peak was observed just below Tc, indicating conventional s-wave superconductivity. In contrast, the coherence peak disappears at 3.1 GPa, suggesting a change in superconducting symmetry to the p-wave dominant state against pressure.

This research is collaborative research with ISSP at the University of Tokyo and Okayama University. The results are published as a letter in the Journal of Physical Society of Japan. Click here for the preprint. Click here for an explanation via YouTube.

Pressure dependence of nuclear spin lattice relaxation rate depending on temperature. A simulation is also included.
(Inset) Pressure dependence of 1/T1T at 2.5K (normal state)

Article information

Kitagawa, S; Ishida, K; Kobayashi, T C; Matsubayashi, Y; Hirai, D; Hiroi, Z

Variation in Superconducting Symmetry Against Pressure on Noncentrosymmetric Superconductor Cd2Re2O7 Revealed by 185/187Re Nuclear Quadrupole Resonance Journal Article

In: Journal of the Physical Society of Japan, vol. 89, no. 5, pp. 053701, 2020.

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