Electrical and thermal transport properties of the kagome metals ATi3Bi5 (A = Rb, Cs)
Electrical and thermal transport properties of the kagome metals ATi3Bi5 (A = Rb, Cs)
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DOI：
10.1103/physrevb.107.174510
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发表时间：
2023-05-10
影响因子：
3.7
通讯作者：
He, Mingquan
中科院分区：
文献类型：
--
作者：
Chen, Xintong;Liu, Xiangqi;He, Mingquan
报道了Kagome单晶金属ATi3Bi5(A=Rb，Cs)的电学和热输运性质。与结构相似的Kagome超导体AV3Sb5不同，ATi3Bi5中没有发现电荷密度波不稳定性。在低于5K的低温下，如磁化测量所见，在ATi3Bi5中出现了超导电性的特征。然而，比热结果并不能证明大块超导电性。与AV3Sb5类似，ATi3Bi5在约70K以下表现出霍尔效应的非线性磁场依赖关系，表明具有多带特性。与声子和电子-声子耦合在热输运中起重要作用的AV3Sb5不同，ATi3Bi5的导热系数主要由电子贡献决定。此外，我们计算的ATi3Bi5的电子结构表明，van Hove奇点位于费米能量之上。与AV3Sb5相比，ATi3Bi5中没有电荷有序与电声子耦合和/或van Hove奇点的贡献密切相关。
We report electrical and thermal transport properties of single-crystalline kagome metals ATi3Bi5 (A = Rb, Cs). Different from the structrually similar kagome superconductors AV3Sb5, no charge density wave instabilities are found in ATi3Bi5. At low temperatures below 5 K, signatures of superconductivity appear in ATi3Bi5 as seen in magnetization measurements. However, bulk superconductivity is not evidenced by specific heat results. Similar to AV3Sb5, ATi3Bi5 show a nonlinear magnetic field dependence of the Hall effect below about 70 K, pointing to a multiband nature. Unlike AV3Sb5 in which phonons and electron-phonon coupling play important roles in thermal transport, the thermal conductivity in ATi3Bi5 is dominated by electronic contributions. Moreover, our calculated electronic structures of ATi3Bi5 suggest that van Hove singularities are sitting well above the Fermi energy. Compared with AV3Sb5, the absence of charge orders in ATi3Bi5 is closely associated with minor contributions from electron-phonon coupling and/or van Hove singularities.