论文标题
通过应变调节揭示的基于Fe的超导体的列量量临界值
Nematic quantum criticality in an Fe-based superconductor revealed by strain-tuning
论文作者
论文摘要
量子关键性被认为是对广泛的外来电子行为的理解至关重要的，包括繁重的费米昂和非常规的超导性，但是在许多当前感兴趣的材料中，量子关键波动的结论性证据是难以捉摸的。量子关键性的一个预期特征是热力学量的功率定律行为是接近量子临界点（QCP）的非热音调参数的函数。在目前的工作中，我们观察到耦合的nematic/结构相变的临界温度的功率定律行为是代表性的基于Fe的超导体家族中单轴应激的函数。我们的测量值提供了该材料中量子关键列的波动的直接证据。此外，这些量子临界波动不限制在QCP周围的狭窄状态内，而是在广泛的温度和调谐参数上延伸。
Quantum criticality has been invoked as being essential to the understanding of a wide range of exotic electronic behavior, including heavy Fermion and unconventional superconductivity, but conclusive evidence of quantum critical fluctuations has been elusive in many materials of current interest. An expected characteristic feature of quantum criticality is power law behavior of thermodynamic quantities as a function of a non-thermal tuning parameter close to the quantum critical point (QCP). In the present work, we observe power law behavior of the critical temperature of the coupled nematic/structural phase transition as a function of uniaxial stress in a representative family of Fe-based superconductors. Our measurements provide direct evidence of quantum critical nematic fluctuations in this material. Furthermore, these quantum critical fluctuations are not confined within a narrow regime around the QCP, but extend over a wide range of temperatures and tuning parameters.
