Bibliographic Details
| Title: |
Enhancement of superconductivity by pressure-induced critical ferromagnetic fluctuations in UCoGe |
| Authors: |
Manago, Masahiro, Kitagawa, Shunsaku, Ishida, Kenji, Deguchi, Kazuhiko, Sato, Noriaki K., Yamamura, Tomoo |
| Source: |
Physical Review B 99, 020506(R) (2019) |
| Publication Year: |
2019 |
| Collection: |
Condensed Matter |
| Subject Terms: |
Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Superconductivity |
| More Details: |
A $^{59}$Co nuclear quadrupole resonance (NQR) was performed on a single-crystalline ferromagnetic (FM) superconductor UCoGe under pressure. The FM phase vanished at a critical pressure $P_c$, and the NQR spectrum just below $P_c$ showed phase separation of the FM and paramagnetic (PM) phases below Curie temperature $T_{\textrm{Curie}}$, suggesting first-order FM quantum phase transition (QPT). We found that the internal field was absent above $P_c$, but the superconductivity is almost unchanged. This result suggests the existence of the nonunitary to unitary transition of the superconductivity around $P_c$. Nuclear spin-lattice relaxation rate $1/T_1$ showed the FM critical fluctuations around $P_c$, which persist above $P_c$ and are clearly related to superconductivity in the PM phase. This FM QPT is understood to be a weak first order with critical fluctuations. $1/T_1$ sharply decreased in the superconducting (SC) state above $P_c$ with a single component, in contrast to the two-component $1/T_1$ in the FM SC state, indicating that the inhomogeneous SC state is a characteristic feature of the FM SC state in UCoGe.
Comment: 5 pages, 4 figures |
| Document Type: |
Working Paper |
| DOI: |
10.1103/PhysRevB.99.020506 |
| Access URL: |
http://arxiv.org/abs/1901.08699 |
| Accession Number: |
edsarx.1901.08699 |
| Database: |
arXiv |
