Anomalous Change in the de Haas-van Alphen Oscillations of CeCoIn_{5} at Ultralow Temperatures.
Anomalous Change in the de Haas-van Alphen Oscillations of CeCoIn_{5} at Ultralow Temperatures.
复制标题
DOI：
10.1103/physrevlett.120.177201
复制
发表时间：
2018-03
影响因子：
8.6
通讯作者：
H. Shishido;Shogo Yamada;K. Sugii;M. Shimozawa;Y. Yanase;M. Yamashita
中科院分区：
文献类型：
--
作者：
H. Shishido;Shogo Yamada;K. Sugii;M. Shimozawa;Y. Yanase;M. Yamashita
我们对重费米子超导体 CeCoIn_{5} 进行 de Haas-van Alphen (dHvA) 测量，测量温度低至高于上临界场 2 mK。我们发现 dHvA 振幅显示出异常抑制，同时 dHvA 频率发生偏移，低于转变温度 T_{n}=20 mK。我们认为这种变化是由于 T_{n} 以下出现的场致反铁磁 (AFM) 态引起的磁击穿，揭示了 CeCoIn_{5} 中场致量子临界点 (QCP) 的起源。发现 T_{n} 的场依赖性对于 7-10 T 非常弱，这意味着通过抑制 AFM QCP 附近的临界自旋涨落来增强 AFM 阶数与 AFM 相位上的场抑制效果相竞争。我们认为，场诱导 AFM 相的出现是非常规超导体的一般特征，它出现在 AFM QCP 附近，包括 CeCoIn_{5}、CeRhIn_{5} 和高 T_{c} 铜酸盐。
We perform de Haas-van Alphen (dHvA) measurements of the heavy-fermion superconductor CeCoIn_{5} down to 2 mK above the upper critical field. We find that the dHvA amplitudes show an anomalous suppression, concomitantly with a shift of the dHvA frequency, below the transition temperature T_{n}=20 mK. We suggest that the change is owing to magnetic breakdown caused by a field-induced antiferromagnetic (AFM) state emerging below T_{n}, revealing the origin of the field-induced quantum critical point (QCP) in CeCoIn_{5}. The field dependence of T_{n} is found to be very weak for 7-10 T, implying that an enhancement of AFM order by suppressing the critical spin fluctuations near the AFM QCP competes with the field suppression effect on the AFM phase. We suggest that the appearance of a field-induced AFM phase is a generic feature of unconventional superconductors, which emerge near an AFM QCP, including CeCoIn_{5}, CeRhIn_{5}, and high-T_{c} cuprates.