Anomalously low electronic thermal conductivity in metallic vanadium dioxide
Anomalously low electronic thermal conductivity in metallic vanadium dioxide
复制标题
金属二氧化钒的电子热导率异常低
DOI：
10.1126/science.aag0410
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发表时间：
2017-01-27
期刊：
影响因子：
56.9
通讯作者：
Wu, Junqiao
中科院分区：
文献类型：
--
作者：
Sangwook, Lee;Hippalgaonkar, Kedar;Wu, Junqiao
在导电固体中，Wiedemann-Franz定律要求电子对热导率的贡献与电导率成比例。违反维德曼-弗朗兹定律通常是非常规准粒子动力学的指示，例如非弹性散射，或电荷载流子的流体动力学集体运动，通常仅在低温下明显。我们报告了在金属二氧化钒的金属-绝缘体转变附近的温度范围从240到340开尔文的Wiedemann-Franz定律的数量级击穿。与先前建立的机制不同，异常低的电子热导率是在热和电荷独立扩散的强关联电子流体中不存在准粒子的特征。
In electrically conductive solids, the Wiedemann-Franz law requires the electronic contribution to thermal conductivity to be proportional to electrical conductivity. Violations of the Wiedemann-Franz law are typically an indication of unconventional quasiparticle dynamics, such as inelastic scattering, or hydrodynamic collective motion of charge carriers, typically pronounced only at cryogenic temperatures. We report an order-of-magnitude breakdown of the Wiedemann-Franz law at high temperatures ranging from 240 to 340 kelvin in metallic vanadium dioxide in the vicinity of its metal-insulator transition. Different from previously established mechanisms, the unusually low electronic thermal conductivity is a signature of the absence of quasiparticles in a strongly correlated electron fluid where heat and charge diffuse independently.