该研究团队通过基于同步辐射的Mssbauer光谱，研究了β-YbAlB4奇异金属相在温度和压力变化下的电荷涨落规律。研究发现，在费米液体区域中，通常的单吸收峰在进入临界区域时会分裂为两个峰。研究团队将这种光谱解释为一种单核跃迁，受到附近电子价态涨落的调制，这些涨落的长时间尺度又被带电极化子的形成进一步增强。这些临界电荷涨落可能是奇异金属的独特特征之一。
据介绍，要理解量子材料中局域边缘处发展起来的奇怪金属行为，就需要探索潜在的电子电荷动力学。
附：英文原文
Title: Observation of a critical charge mode in a strange metal
Author: Hisao Kobayashi, Yui Sakaguchi, Hayato Kitagawa, Momoko Oura, Shugo Ikeda, Kentaro Kuga, Shintaro Suzuki, Satoru Nakatsuji, Ryo Masuda, Yasuhiro Kobayashi, Makoto Seto, Yoshitaka Yoda, Kenji Tamasaku, Yashar Komijani, Premala Chandra, Piers Coleman
Issue&Volume: 2023-03-03
Abstract: Understanding the strange metallic behavior that develops at the brink of localization in quantum materials requires probing the underlying electronic charge dynamics. Using synchrotron radiation–based Mssbauer spectroscopy, we studied the charge fluctuations of the strange metal phase of β-YbAlB4 as a function of temperature and pressure. We found that the usual single absorption peak in the Fermi-liquid regime splits into two peaks upon entering the critical regime. We interpret this spectrum as a single nuclear transition, modulated by nearby electronic valence fluctuations whose long time scales are further enhanced by the formation of charged polarons. These critical charge fluctuations may prove to be a distinct signature of strange metals.
DOI: abc4787
Source: https://www.science.org/doi/10.1126/science.abc4787