Solvable theory of a strange metal at the breakdown of a heavy Fermi liquid
Solvable theory of a strange metal at the breakdown of a heavy Fermi liquid
复制标题
重费米液体分解时奇异金属的可解理论
作者：
Erik E. Aldape;Taylor Cookmeyer;A. A. Patel;E. Altman
我们介绍了一个有效的理论量子临界点的重费米子系统涉及的载流子密度的变化，而不对称性破缺。新的理论捕捉到一个强耦合金属固定点，导致强大的边缘费米液体传输现象，在一个受控的大$N$限制。这与传统的所谓的“奴隶玻色子”理论的近藤崩溃，其中大的$N$限制描述了一个弱耦合固定点和非平凡的运输行为可能只能通过不受控制的$1/N$修正。我们计算的有效模型内的弱场霍尔系数的系统是跨过渡调谐。我们发现，在两个平台之间，反映了不同的载流子密度在两个费米液相，霍尔系数可以开发一个峰值的临界交叉制度，与最近的实验结果相一致。在紧急玻色子激发的强阻尼区，临界点也显示出近似普适的“普朗克”输运寿命， Au_{mathrm{tr}}Simhbar/（k_BT）$。
We introduce an effective theory for quantum critical points in heavy fermion systems involving a change in carrier density without symmetry breaking. The new theory captures a strong coupling metallic fixed point, leading to robust marginal Fermi liquid transport phenomenology, within a controlled large $N$ limit. This is contrasted with the conventional so-called "slave boson" theory of the Kondo breakdown, where the large $N$ limit describes a weak coupling fixed point and non-trivial transport behavior may only be obtained through uncontrolled $1/N$ corrections. We compute the weak field Hall coefficient within the effective model as the system is tuned across the transition. We find that between the two plateaus, reflecting the different carrier densities in the two Fermi liquid phases, the Hall coefficient can develop a peak in the critical crossover regime, consistent with recent experimental findings. In the regime of strong damping of emergent bosonic excitations, the critical point also displays a near-universal "Planckian" transport lifetime, $ au_{mathrm{tr}}simhbar/(k_BT)$.