Novel superconductivity on the magnetic criticality in heavy-fermion systems : a systematic study of NQR under pressure
| dc.creator | Kitaoka, Y. | |
| dc.creator | Kawasaki, S. | |
| dc.creator | Kawasaki, Y. | |
| dc.creator | Mito, T. | |
| dc.creator | Zheng, G. -q. | |
| dc.date | 2004-05-16 | |
| dc.date.accessioned | 2026-07-07T02:58:10Z | |
| dc.date.available | 2026-07-07T02:58:10Z | |
| dc.description | We report the discovery of exotic superconductivity (SC) and novel magnetism in heavy-fermion (HF) compounds, CeCu$_2$Si$_2$, CeRhIn$_5$ and CeIn$_3$ through nuclear-quadrupole-resonance (NQR) measurements under pressure ($P$). The exotic SC in a homogeneous CeCu$_2$Si$_2$ revealed antiferromagnetic critical fluctuations at the border to antiferromagnetism (AFM) or marginal AFM. The uniform mixed phase of SC and AFM in CeCu$_2$(Si$_{1-x}$Ge$_x$)$_2$ emerges on a microscopic level, once a tiny amount of 1%Ge($x=0.01$) is substituted for Si to expand its lattice. The application of minute pressure ($P\sim 0.19$ GPa) suppresses the sudden emergence of the AFM caused by doping Ge. The persistence of the low-lying magnetic excitations at temperatures lower than $T_c$ and $T_N$ is ascribed due to the uniform mixed phase of SC and AFM. Likewise, the $P$-induced HF superconductor CeRhIn$_5$ coexists with AFM on a microscopic level in $P = 1.5$ - 1.9 GPa. The unconventional gapless nature of SC in the low-lying excitation spectrum emerges due to the uniform mixed phase of AFM and SC. By contrast, in CeIn$_3$, we propose that the magnetic excitations such as spin-density fluctuations induced by the first-order phase transition from the AFM to the paramagnetism (PM) might mediate attractive interaction to form the Cooper pairs in the novel phase of AFM. | |
| dc.description | 11 pages, 13 figures | |
| dc.identifier | https://arxiv.org/abs/cond-mat/0405348 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/0405348 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/23969 | |
| dc.subject | Strongly Correlated Electrons | |
| dc.subject | Superconductivity | |
| dc.title | Novel superconductivity on the magnetic criticality in heavy-fermion systems : a systematic study of NQR under pressure | |
| dc.type | text |