论文标题
通过波动光谱研究的几何沮丧有机导体中电荷 - 结晶和电荷玻璃状态的比较
Comparison of the charge-crystal and charge-glass state in geometrically frustrated organic conductors studied by fluctuation spectroscopy
论文作者
论文摘要
我们对有机导体的不同充电状态$θ$ - （bedt-ttf）的低频电荷载体动力学进行了系统调查。由于具有强的电子相关性，这些材料表现出电荷顺序的过渡，可以通过快速冷却来避免这种材料，从而导致所谓的电荷玻璃状态，而没有远距离顺序。波动光谱和热脉冲方法的组合使我们能够研究和比较低阻力淬火和高电荷订购的状态的阻力波动，从而揭示了各自的噪声幅度的显着差异。对于两种化合物，我们在金属 - 绝缘体过渡时发现了强烈增强的电阻波动，并且在缓慢冷却的电荷 - 结晶状态下最大噪声最大，部分主导了两级过程，揭示了特征激活能量。
We present a systematic investigation of the low-frequency charge carrier dynamics in different charge states of the organic conductors $θ$-(BEDT-TTF)$_2$$M$Zn(SCN)$_4$ with $M$=Rb,Tl, 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.
