TY - JOUR
T1 - Localized-to-itinerant transition preceding antiferromagnetic quantum critical point and gapless superconductivity in CeRh0.5Ir0.5In5
AU - Kawasaki, Shinji
AU - Oka, Toshihide
AU - Sorime, Akira
AU - Kogame, Yuji
AU - Uemoto, Kazuhiro
AU - Matano, Kazuaki
AU - Guo, Jing
AU - Cai, Shu
AU - Sun, Liling
AU - Sarrao, John L.
AU - Thompson, Joe D.
AU - Zheng, Guo qing
N1 - Funding Information:
We would like to thank T. Kambe for help with the susceptibility measurement, Y. Fuseya, Y. Kuramoto, H. Kusunose, J. Otsuki, K. Miyake, S. Watanabe, T. Oguchi, and Q. Si for discussion. This work was supported in part by research grants from MEXT (Nos. JP19K03747, JP23102717, and JP25400374), NSFC grant No. 11634015 and MOST Grant (Nos. 2016YFA0300300, 2017YFA0302904, and 2017YFA0303103) and at Los Alamos, was performed under the auspices of the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering.
Publisher Copyright:
© 2020, The Author(s).
PY - 2020/12/1
Y1 - 2020/12/1
N2 - A fundamental problem posed from the study of correlated electron compounds, of which heavy-fermion systems are prototypes, is the need to understand the physics of states near a quantum critical point (QCP). At a QCP, magnetic order is suppressed continuously to zero temperature and unconventional superconductivity often appears. Here, we report pressure (P)-dependent 115In nuclear quadrupole resonance (NQR) measurements on heavy-fermion antiferromagnet CeRh0.5Ir0.5In5. These experiments reveal an antiferromagnetic (AF) QCP at PcAF=1.2 GPa where a dome of superconductivity reaches a maximum transition temperature Tc. Preceding PcAF, however, the NQR frequency νQ undergoes an abrupt increase at Pc* = 0.8 GPa in the zero-temperature limit, indicating a change from localized to itinerant character of cerium’s f-electron and associated small-to-large change in the Fermi surface. At PcAF where Tc is optimized, there is an unusually large fraction of gapless excitations well below Tc that implicates spin-singlet, odd-frequency pairing symmetry.
AB - A fundamental problem posed from the study of correlated electron compounds, of which heavy-fermion systems are prototypes, is the need to understand the physics of states near a quantum critical point (QCP). At a QCP, magnetic order is suppressed continuously to zero temperature and unconventional superconductivity often appears. Here, we report pressure (P)-dependent 115In nuclear quadrupole resonance (NQR) measurements on heavy-fermion antiferromagnet CeRh0.5Ir0.5In5. These experiments reveal an antiferromagnetic (AF) QCP at PcAF=1.2 GPa where a dome of superconductivity reaches a maximum transition temperature Tc. Preceding PcAF, however, the NQR frequency νQ undergoes an abrupt increase at Pc* = 0.8 GPa in the zero-temperature limit, indicating a change from localized to itinerant character of cerium’s f-electron and associated small-to-large change in the Fermi surface. At PcAF where Tc is optimized, there is an unusually large fraction of gapless excitations well below Tc that implicates spin-singlet, odd-frequency pairing symmetry.
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U2 - 10.1038/s42005-020-00418-x
DO - 10.1038/s42005-020-00418-x
M3 - Article
AN - SCOPUS:85089963820
SN - 2399-3650
VL - 3
JO - Communications Physics
JF - Communications Physics
IS - 1
M1 - 148
ER -