arXiv 1602.080692016-02cond-mat.str-elcond-mat.mtrl-scicond-mat.supr-con

Vortexlike excitations in the heavy-fermion superconductor CeIrIn$_5$

Yongkang Luo, P. F. S. Rosa, E. D. Bauer, J. D. Thompson

备注：: 6 pages, 4 figures
发表信息：: Phys. Rev. B 93, 201102 (2016)
DOI：: 10.1103/PhysRevB.93.201102

英文摘要：

We report a systematic study of temperature- and field-dependent charge ($\boldsymbolρ$) and entropy ($\mathbf{S}$) transport in the heavy-fermion superconductor CeIrIn$_5$. Its large positive thermopower $S_{xx}$ is typical of Ce-based Kondo lattice systems, and strong electronic correlations play an important role in enhancing the Nernst signal $S_{xy}$. By separating the off-diagonal Peltier coefficient $α_{xy}$ from $S_{xy}$, we find that $α_{xy}$ becomes positive and greatly enhanced at temperatures well above the bulk $T_c$. Compared with the non-magnetic analog LaIrIn$_5$, these results suggest vortexlike excitations in a precursor state to unconventional superconductivity in CeIrIn$_5$. This study sheds new light on the similarity of heavy-fermion and cuprate superconductors and on the possibility of states not characterized by the amplitude of an order parameter.

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