The electrical-resistivity study for Ni-doped CeCoIn5 reveals the unique characteristic of the quantum critical point (QCP) originating from the hidden antiferromagnetic order parameter; the QCP follows the breakdown of the superconducting state. We demonstrate that in Ni-doped CeCoIn5, the signatures of the QCP in the electrical resistivity always occur at the superconducting upper critical field Hc2 while Hc2 monotonically decreases to zero with increasing Ni concentrations. This characteristic is expected to cause the exotic nature of superconductivity in the prototypical unconventional superconductor CeCoIn5.
The article regarding this work:
A. Yashiro, Rahmanto, K. Inami, K. Suzuki, K. Inoh, T. Takahashi, R. Koizumi, Y. Kono, S. Kittaka, Y. Shimizu, F. Honda, D. Aoki, K. Tenya, and M. Yokoyama:
"Quantum criticality linked to the suppressed superconducting upper critical field in Ni-doped CeCoIn5",
Physical Review Materials 8, L081801 (2024).
link to this paper