Caprara Sergio, Di Castro Carlo, Mirarchi Giovanni, Seibold Götz, Grilli Marco
Istituto dei Sistemi Complessi-Consiglio Nazionale delle Ricerche and Dipartimento di Fisica, Università di Roma Sapienza, Piazzale Aldo Moro 5, 00185 Roma, Italy.
Institut für Theoretische Physik und Astrophysik, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
Materials (Basel). 2024 Nov 28;17(23):5849. doi: 10.3390/ma17235849.
In a recent paper [B. Michon et al., Nat. Commun. (2023) 14:3033], optical conductivity experiments in cuprate superconductors were shown to display scaling properties consistent with the Marginal Fermi Liquid theory. Here, we argue that the temperature regime studied in these experiments does not allow for distinguishing between Marginal Fermi Liquid and Shrinking Fermi Liquid. In the latter scenario, which we recently proposed and which applies near a quantum critical point, dynamical fluctuations of the order parameter with a short correlation length mediate a nearly isotropic scattering among the quasiparticles over the entire Fermi surface leading to strange metal behavior. If the damping of these nearly local fluctuations increases by decreasing the temperature, the Fermi liquid regime shrinks and the strange metal behavior is extended to the lowest temperatures. This Shrinking Fermi Liquid scenario has many similarities and some differences with respect to the Marginal Fermi Liquid theory. In particular, we show that the approximate scaling properties of the optical conductivity in some high-frequency regimes predicted by the Shrinking Fermi Liquid scenario account for a very good description of the experimental data.
在最近的一篇论文[B. 米雄等人，《自然·通讯》(2023) 14:3033]中，铜酸盐超导体中的光导率实验显示出与边缘费米液体理论一致的标度性质。在此，我们认为这些实验所研究的温度范围无法区分边缘费米液体和收缩费米液体。在我们最近提出的、适用于接近量子临界点的后一种情形中，具有短关联长度的序参量的动力学涨落介导了整个费米面附近准粒子之间近乎各向同性的散射，从而导致奇异金属行为。如果这些近乎局域涨落的阻尼通过降低温度而增加，费米液体区域就会收缩，奇异金属行为会扩展到最低温度。这种收缩费米液体情形与边缘费米液体理论有许多相似之处，也有一些不同之处。特别是，我们表明收缩费米液体情形所预测的某些高频区域光导率的近似标度性质能够很好地描述实验数据。
