论文标题
沉重的费米恩奇怪金属Planckian吗？
Are Heavy Fermion Strange Metals Planckian?
论文作者
论文摘要
奇怪的金属行为是指在低于Mott-Ioffe-Regel极限下的温度下电阻率的线性温度依赖性。它在许多密切相关的电子系统中可以看到，从重型费米亚化合物，通过过渡金属氧化物和铁pnictides到魔术角扭曲的双层石墨烯，经常与非常规或“高温”超导性有关。在不同材料类别中，对这些现象的统一理解是凝结物理学的核心开放问题。测试是否可能由Planckian耗散来决定线性 - 温度定律 - 散射$ \ sim k _ {\ rm B} t/\ hbar $，都引起了人们的关注。在这里，我们评估了奇怪的金属重型费米化合物的情况。它们允许探测极端相关强度的状态，有效的质量或费米速度的速度重新量量超过三个数量级。采用与以前的研究相同的程序，即假定具有上述散射速率的简单drude电导率，我们发现，对于这些强烈重新归一化的准粒子，散射比Planckian弱得多，这意味着线性温度依赖性应是由于其他影响。我们讨论了这一发现的含义，并指出了进一步工作的方向。
Strange metal behavior refers to a linear temperature dependence of the electrical resistivity at temperatures below the Mott-Ioffe-Regel limit. It is seen in numerous strongly correlated electron systems, from the heavy fermion compounds, via transition metal oxides and iron pnictides, to magic angle twisted bi-layer graphene, frequently in connection with unconventional or "high temperature" superconductivity. To achieve a unified understanding of these phenomena across the different materials classes is a central open problem in condensed matter physics. Tests whether the linear-in-temperature law might be dictated by Planckian dissipation - scattering with the rate $\sim k_{\rm B}T/\hbar$, are receiving considerable attention. Here we assess the situation for strange metal heavy fermion compounds. They allow to probe the regime of extreme correlation strength, with effective mass or Fermi velocity renormalizations in excess of three orders of magnitude. Adopting the same procedure as done in previous studies, i.e., assuming a simple Drude conductivity with the above scattering rate, we find that for these strongly renormalized quasiparticles, scattering is much weaker than Planckian, implying that the linear temperature dependence should be due to other effects. We discuss implications of this finding and point to directions for further work.
