Comparison of the charge-crystal and charge-glass state in geometrically frustrated organic conductors studied by fluctuation spectroscopy
Comparison of the charge-crystal and charge-glass state in geometrically frustrated organic conductors studied by fluctuation spectroscopy
复制标题
通过涨落光谱研究几何受阻有机导体中电荷晶体和电荷玻璃态的比较
DOI：
10.1103/physrevb.105.205111
复制
发表时间：
2022
影响因子：
3.7
通讯作者：
Yamamoto Hiroshi M.
中科院分区：
文献类型：
--
作者：
Thomas Tatjana;Thyzel Tim;Sun Hungwei;Muller Jens;Hashimoto Kenichiro;Sasaki Takahiko;Yamamoto Hiroshi M.
我们系统地研究了有机导体在不同电荷状态下的低频载流子动力学，这是由于几何受挫三角形晶格上的电荷自由度被淬火或放松所导致的。由于强电子相关性，这些材料表现出电荷有序转变，可以通过快速冷却产生所谓的无长程有序的电荷玻璃态来动力学地避免这种转变。波动光谱与热脉冲方法的结合使我们能够研究和比较低阻猝灭状态和高阻电荷有序状态下的电阻波动，揭示出各自噪声量级的显著差异。对于这两种化合物，我们发现在金属-绝缘体跃迁处电阻波动强烈增强，在缓慢冷却的电荷晶体状态下噪声最大，部分占主导地位的两能级过程显示出特征活化能。
We present a systematic investigation of the low-frequency charge carrier dynamics in different charge states of the organic conductorswith, which result from quenching or relaxing the charge degrees of freedom on a geometrically frustrated triangular lattice. Due to strong electronic correlations these materials exhibit a charge-ordering transition, which can be kinetically avoided by rapid cooling resulting in a so-called charge-glass state without long-range order. The combination of fluctuation spectroscopy and a heat pulse method allows us to study and compare the resistance fluctuations in the low-resistive quenched and the high-resistive charge-ordered state, revealing striking differences in the respective noise magnitudes. For both compounds, we find strongly enhanced resistance fluctuations right at the metal-insulator transition and a broad noise maximum in the slowly cooled charge-crystal state with partly dominating two-level processes revealing characteristic activation energies.