TY - JOUR
T1 - Pairing interaction in superconducting UCoGe tunable by magnetic field
AU - Ishida, K.
AU - Matsuzaki, S.
AU - Manago, M.
AU - Hattori, T.
AU - Kitagawa, S.
AU - Hirata, M.
AU - Sasaki, T.
AU - Aoki, D.
N1 - Funding Information:
K.I. wishes to acknowledge V. P. Mineev for the theoretical inputs and fruitful discussions and K. Deguchi, T. Yamamura, and N. K. Sato for the long-term collaboration on UCoGe. We thank Y. Ihara, Y. Tokunaga, S. Yonezawa, Y. Maeno, H. Harima, H. Ikeda, S. Fujimoto, Y. Tada, A. de Visser, J.-P. Brison, G. Knebel, and J. Flouquet for fruitful discussions. This work was supported by the Kyoto University LTM Center, Tohoku University (Projects No. 202012-HMKPB-0052 and No. 202012-IPKAC-0008), Grants-in-Aid for Scientific Research (Grants No. JP15H05745, No. JP17K14339, No. JP19K03726, No. JP16KK0106, No. JP19K14657, No. JP19H00646, No. JP19H04696, No. JP20H00130, and No. JP20KK0061, and a Grant-in-Aid for JSPS Research Fellows (Grant No. JP20J11939) from JSPS. We would like to thank Editage in Ref. for English language editing.
Publisher Copyright:
© 2021 American Physical Society.
PY - 2021/10/1
Y1 - 2021/10/1
N2 - The mechanism of unconventional superconductivity, such as high-temperature-cuprate, Fe-based, and heavy-fermion superconductors, has been studied as a central issue in condensed-matter physics. Spin fluctuations, instead of phonons, are considered to be responsible for the formation of Cooper pairs, and many efforts have been made to confirm this mechanism experimentally. Although a qualitative consensus seems to have been obtained, experimental confirmation has not yet been achieved. This is owing to a lack of the quantitative comparison between theory and experiments. Here, we show a semiquantitative comparison between the superconducting-transition temperature (TSC) and spin fluctuations derived from the NMR experiment on the ferromagnetic (FM) superconductor UCoGe in which the FM fluctuations and superconductivity are tunable by external fields. The enhancement and abrupt suppression of TSC by applied fields, as well as the pressure variation of TSC around the FM criticality are well understood by the change in the FM fluctuations on the basis of the single-band spin-triplet theoretical formalism. The present comparisons strongly support the theoretical formalism of spin-fluctuation-mediated superconductivity, particularly in UCoGe.
AB - The mechanism of unconventional superconductivity, such as high-temperature-cuprate, Fe-based, and heavy-fermion superconductors, has been studied as a central issue in condensed-matter physics. Spin fluctuations, instead of phonons, are considered to be responsible for the formation of Cooper pairs, and many efforts have been made to confirm this mechanism experimentally. Although a qualitative consensus seems to have been obtained, experimental confirmation has not yet been achieved. This is owing to a lack of the quantitative comparison between theory and experiments. Here, we show a semiquantitative comparison between the superconducting-transition temperature (TSC) and spin fluctuations derived from the NMR experiment on the ferromagnetic (FM) superconductor UCoGe in which the FM fluctuations and superconductivity are tunable by external fields. The enhancement and abrupt suppression of TSC by applied fields, as well as the pressure variation of TSC around the FM criticality are well understood by the change in the FM fluctuations on the basis of the single-band spin-triplet theoretical formalism. The present comparisons strongly support the theoretical formalism of spin-fluctuation-mediated superconductivity, particularly in UCoGe.
UR - http://www.scopus.com/inward/record.url?scp=85118474079&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85118474079&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.104.144505
DO - 10.1103/PhysRevB.104.144505
M3 - Article
AN - SCOPUS:85118474079
SN - 2469-9950
VL - 104
JO - Physical Review B
JF - Physical Review B
IS - 14
M1 - A31
ER -