Competing magnetic orders in the superconducting state of heavy-fermion CeRhIn5
Competing magnetic orders in the superconducting state of heavy-fermion CeRhIn5
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DOI：
10.1073/pnas.1703016114
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发表时间：
2017-05-23
影响因子：
11.1
通讯作者：
Thompson, J. D.
中科院分区：
文献类型：
--
作者：
Rosa, P. F. S.;Kang, J.;Thompson, J. D.
施加的压力将重费米子反铁磁体CeRhIn5推向一个量子临界点，这个临界点被一个非常规的超导圆顶所隐藏。磁场抑制了超导圆顶，揭示了局域特征的量子相变。在这里，我们证明了在CeRhIn5的Ce位点上5%的磁取代，无论是Nd还是Gd，都会在超导状态下引起零场磁不稳定。这种磁态不仅应该与高场局域矩磁态具有不同的有序向量，而且还与后者竞争，这表明Nd和Gd杂质在零场中稳定了自旋密度波相位，类似于Ce0:95Nd0:05CoIn5的情况。在模型计算的支持下，我们将这种自旋密度波的不稳定性归因于磁杂质驱动的自旋激子凝聚，这些自旋激子形成于非常规超导状态中。
Applied pressure drives the heavy-fermion antiferromagnet CeRhIn5 toward a quantum critical point that becomes hidden by a dome of unconventional superconductivity. Magnetic fields suppress this superconducting dome, unveiling the quantum phase transition of local character. Here, we show that 5 % magnetic substitution at the Ce site in CeRhIn5, either by Nd or Gd, induces a zero-field magnetic instability inside the superconducting state. This magnetic state not only should have a different ordering vector than the high-field local-moment magnetic state, but it also competes with the latter, suggesting that a spin-densitywave phase is stabilized in zero field by Nd and Gd impurities, similarly to the case of Ce0:95Nd0:05CoIn5. Supported by model calculations, we attribute this spin-density wave instability to a magnetic-impurity-driven condensation of the spin excitons that form inside the unconventional superconducting state.