Recent progress in extremely correlated Fermi liquid theory (ECFL) and dynamical mean field theory (DMFT) enables us to compute in the $d \to \infty$ limit the resistivity of the $t-J$ model after setting $J\to0$. This is also the $U=\infty$ Hubbard model. We study three densities $n=.75,.8,.85$ that correspond to a range between the overdoped and optimally doped Mott insulating state. We delineate four distinct regimes characterized by different behaviors of the resistivity $ρ$. We find at the lowest $T$ a Gutzwiller Correlated Fermi Liquid regime with $ρ\propto T^2$ extending up to an effective Fermi temperature that is dramatically suppressed from the non-interacting value. This is followed by a Gutzwiller Correlated Strange Metal regime with $ρ\propto (T-T_0)$, i.e. a linear resistivity extrapolating back to $ρ=0$ at a positive $T_0$. At a higher $T$ scale, this crosses over into the Bad Metal regime with $ρ\propto (T+T_1)$ extrapolating back to a finite resistivity at $T=0$, and passing through the Ioffe-Regel-Mott value where the mean free path is a few lattice constants. This regime finally gives way to the High $T$ Metal regime, where we find $ρ\propto T$. The present work emphasizes the first two, where the availability of an analytical ECFL theory is of help in identifying the changes in related variables entering the resistivity formula that accompany the onset of linear resistivity, and the numerically exact DMFT helps to validate the results. We also examine thermodynamic variables such as the magnetic susceptibility, compressibility, heat capacity and entropy, and correlate changes in these with the change in resistivity. This exercise casts valuable light on the nature of charge and spin correlations in the strange metal regime, which has features in common with the physically relevant strange metal phase seen in strongly correlated matters.
Extended Hubbard model with renormalized Wannier wave functions in the correlated state III: Statistically consistent Gutzwiller approximation and the metallization of atomic solid hydrogen
Strange metal behavior in a pure ferromagnetic Kondo lattice
在量子临界点(QCP)附近的各种材料中发现的奇怪的金属相,构成了一个长期的谜团。奇异金属与非常规超导性和反铁磁QCP的频繁联系使人们相信它们是高度纠缠的量子态。相比之下,铁磁体被认为是奇怪金属的不太可能的设置,因为它们是弱纠缠的,并且它们的QCP经常被竞争相或一阶相变打断。在这里,我们提供了令人信服的证据表明,化学计量的重费米子铁磁体CeRh $_6$ Ge $_4$成为一个奇怪的金属在压力引起的QCP:比热和电阻率测量表明,FM过渡不断抑制到零温度揭示了一个奇怪的金属相。我们认为,强磁各向异性在这个过程中起着关键作用,注入纠缠,在三重共振价键(tRVB)的形式进入有序的铁磁体。我们发现,从tRVB到近藤单线发生在QCP的奇异变换导致费米表面体积的跳跃:奇怪的金属行为的关键驱动程序。我们的研究结果为FM量子临界性的研究开辟了一个新的方向,同时也为奇怪的金属问题建立了一个重要的新环境。最重要的是,在FM量子临界点的奇怪金属行为表明,它是量子纠缠,而不是反铁磁性的破坏,这是许多不同的奇怪金属行为的例子的共同驱动力。
Is the optical conductivity of heavy fermion strange metals Planckian?
奇怪的金属行为出现在各种凝聚态环境中,实现普遍的理解是一个令人兴奋的前景。近藤破坏的超越朗道量子临界性在描述奇异金属重费米子化合物的行为方面取得了相当大的成功,并且有一些证据表明相关的部分定域-离域性质可以推广到不同的材料类别。其他潜在的支配性原则也在探讨之中。一个有趣的假设是,普朗克散射的速率为$k_{\rm B}T/\hbar$,导致(直流)电阻率的线性温度依赖性,这是奇怪的金属行为的标志。在这里,我们扩展了以前介绍的分析方案的基础上德鲁德描述的直流电阻率的光电导率数据。当它们被一个简单的(ac)Drude模型很好地描述时,散射率可以直接提取。这避免了需要确定载流子浓度与有效质量的比率,该比率使先前基于直流电阻率的分析复杂化。然而,我们指出,奇怪的金属通常表现出强烈的偏离德鲁德行为,作为例子的“极端”奇怪的金属YbRh $_2$ Si $_2$。这需要替代的方法,我们指出的权力奇怪的金属动力学(能量超过温度)的非弹性部分的光学电导率的标度分析。如果这种标度扩展到低频极限,可以估计出奇异金属的弛豫速率,并最终可以用来测试奇异金属是否以普朗克方式弛豫。
Strange metallicity encompasses high magnetic field-induced superconductivity in UTe2
Charles University, Faculty of Mathematics and Physics(查理大学数学物理学院);Hochfeld-Magnetlabor Dresden (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf(德累斯顿强磁场实验室(HLD-EMFL),德累斯顿罗森多夫亥姆霍兹中心);Cavendish Laboratory, University of Cambridge(剑桥大学卡文迪许实验室)
Critical fluctuations and conserved dynamics in a strange ferromagnetic metal
Zhejiang University(浙江大学);Hubei Normal University(湖北师范大学);University of Cincinnati(辛辛那提大学);Max Planck Institute for Chemical Physics of Solids(马克斯·普朗克固体化学物理研究所)
Transport in the emergent Bose liquid: Bad metal, strange metal, and weak insulator, all in one system
Tsung-Dao Lee Institute & School of Physics and Astronomy, Shanghai Jiao Tong University(上海交大李政道理论与计算中心及物理与天文学院);Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education)(人工结构与量子控制教育部重点实验室);Shanghai Branch, Hefei National Laboratory(合肥国家实验室上海分部)
Crossover of Charge Fluctuations across the Strange Metal Phase Diagram
正常金属表现出价等离子体激元,其是在其传导电子密度中的声波。这种神秘的奇怪金属的特征是非玻尔兹曼输运,违反了最基本的费米液体标度定律。一个基本的问题是:奇怪的金属有等离子体激元吗?利用动量分辨非弹性电子散射(M-EELS),我们最近发现,最佳掺杂的Bi $_{2.1}$ Sr $_{1.9}$ Ca $_{1.0}$ Cu $_{2.0}$ O $_{8+x}$(Bi-2212)在大多数能量和动量尺度上表现出无特征的、与温度无关的连续谱,其形式为幂律[M. Mitrano,PNAS 115,5392-5396(2018)]。在这里,我们表明,这种连续存在于整个扇形,奇怪的金属区域的相图。在该区域之外,观察到光谱权重的急剧变化:在欠掺杂样品中,高达0.5 eV的光谱权重在低温下增强,使系统偏向电荷顺序不稳定。这种情况是相反的过掺杂的情况下,在低温下,光谱权重被强烈抑制,增加准粒子在这个政权的相干性。最佳掺杂对应于这两个相反行为之间的边界,在该边界处,响应与温度无关。我们的研究表明,在Bi-2212中,等离子体激元并不存在定义明确的激发,并且无特征的连续体是奇怪金属的定义属性,它与光谱权重变化发生符号反转的特殊交叉有关。
School of Physical Sciences and Engineering, Beijing Jiaotong University(北京交通大学物理科学与工程学院);Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences(中国科学院物理研究所凝聚态物理国家实验室);Kavli Institute for Theoretical Sciences, University of Chinese Academy of Sciences(中国科学院大学理论科学研究所)
Strange-metal behavior in correlated molecular conductors
Universität Stuttgart(斯图加特大学);Saitama University(埼玉大学);RIKEN Nishina Center(理化学研究所西村研究中心);Shibaura Institute of Technology(芝浦工业大学);University of Tokyo(东京大学);Max Planck Institute for Solid State Research(马克斯·普朗克固体研究所);Institut Néel - CNRS and Université Grenoble Alpes(内耳研究所-法国国家科学研究中心与格勒诺布尔阿尔卑斯大学)