论文标题
fete $ _ {0.5} $ se $ _ {0.5} $的表面状态和旋转互动的传输证据
Transport evidence for the surface state and spin-phonon interaction in FeTe$_{0.5}$Se$_{0.5}$
论文作者
论文摘要
事实证明，铁葡萄构化是由于其独特的电子结构而实施量子计算的固有拓扑超导体。 fete $ _ {0.5} $ se $ _ {0.5} $的拓扑表面状态已通过多个计算进行了预测，然后通过高分辨率的光发射和扫描隧道实验确认。但是，到目前为止，拓扑表面状态的电运证据的切碎仍然存在。通过进行电运输实验，我们可以在超导转换温度附近观察到具有非线性霍尔电导率和同时线性磁场的拓扑过渡。此外，我们观察到大厅系数的符号逆转，并同时在约40 K处同时软化$ {a} _ {1g} $ phonon模式，表明列明过渡。与nematicity同步的声子软化通过自旋形成相互作用表现出增强的波动状态。我们的结果可靠地证实了FETE $ _ {0.5} $ SE $ _ {0.5} $的拓扑表面状态，并提供了对铁硫代基化铁中超导性机制的理解。
The iron chalcogenides have been proved to be intrinsic topological superconductors to implement quantum computation because of their unique electronic structures. The topologically nontrivial surface states of FeTe$_{0.5}$Se$_{0.5}$ have been predicted by several calculations and then confirmed by high-resolution photoemission and scanning tunneling experiments. However, so far, the shreds of the electrical transport evidence for topological surface states are still in absence. By carrying out electrical transport experiments, we observe a topological transition with a nonlinear Hall conductivity and simultaneous linear magnetoresistance near the superconducting transition temperature. Furthermore, we observe a sign reversal of the Hall coefficient accompanied by a concurrently softening of the ${A}_{1g}$ phonon mode at about 40 K, indicating a nematic transition. The synchronized phonon softening with nematicity manifests an enhanced fluctuation state through spin-phonon interaction. Our results solidly corroborate the topological surface states of FeTe$_{0.5}$Se$_{0.5}$ and provide an understanding of the mechanism of the superconductivity in iron chalcogenides.
