1] H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, United Kingdom [2] Magnetic Materials Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan [3].
Sci Rep. 2013 Nov 20;3:3261. doi: 10.1038/srep03261.
The nature of the electronic state of a metal depends strongly on its dimensionality. In a system of isolated conducting chains, the Fermi-liquid (quasiparticle) description appropriate for higher dimensions is replaced by the so-called Tomonaga-Luttinger liquid picture characterized by collective excitations of spin and charge. Temperature is often regarded as a viable tuning parameter between states of different dimensionality, but what happens once thermal broadening becomes comparable to the interchain hopping energy remains an unresolved issue, one that is central to many organic and inorganic conductors. Here we use the ratio of the thermal to electrical conductivities to probe the nature of the electronic state in PrBa₂Cu₄O₈ as a function of temperature. We find that despite the interchain transport becoming non-metallic, the charge carriers within the CuO chains appear to retain their quasiparticle nature. This implies that temperature alone cannot induce a crossover from Fermi-liquid to Tomonaga-Luttinger-liquid behaviour in quasi-one-dimensional metals.
金属的电子态性质强烈依赖于其维度。在孤立的导电线系统中，适用于更高维度的费米液体（准粒子）描述被所谓的汤姆onaga-Luttinger 液体图像所取代，这种图像的特征是自旋和电荷的集体激发。温度通常被认为是不同维度状态之间的可行调谐参数，但一旦热展宽与链间跳跃能相比变得可以比拟，会发生什么情况仍然是一个悬而未决的问题，这个问题是许多有机和无机导体的核心问题。在这里，我们使用热导率与电导率的比值来探测 PrBa₂Cu₄O₈ 中电子态的性质随温度的变化。我们发现，尽管链间输运变得非金属，但 CuO 链中的载流子似乎仍然保留其准粒子性质。这意味着，仅温度本身不能诱导准一维金属从费米液体到汤姆onaga-Luttinger 液体行为的转变。
