论文标题
拓扑绝缘子BI $ _2 $ SE $ _3 $中的热生成旋转电流
Thermally-generated spin current in the topological insulator Bi$_2$Se$_3$
论文作者
论文摘要
我们通过量化热梯度可以生成横向旋转电流的效率来完成拓扑绝缘体BI $ _2 $ SE $ _3 $中完整三合一的热梯度，电荷电流和旋转电流之间的互连的测量。我们通过将旋转的Nernst Magneto-Thermopower与Bi $ _2 $ _2 $ SE $ _3 $/cofeb的双层的旋转霍尔宏伟者进行比较来实现这一目标。我们发现BI $ _2 $ SE $ _3 $确实会产生大量的热驱动旋转电流。旋转电流与热梯度比率的下限为$ j_s/\ nabla_x t $ =（4.9 $ \ pm $ 0.9）$ \ times $ \ times $ 10 $^{6} $（$ \ hbar/2e $） $ - $ 0.61 $ \ pm $ 0.11。 BI $ _2 $ SE $ _3 $的旋转Nernst比率是迄今为止测量的所有材料中最大的，与以前的重金属PT和W的测量值相比，大的2-3倍。
We complete measurements of interconversions among the full triad of thermal gradients, charge currents, and spin currents in the topological insulator Bi$_2$Se$_3$ by quantifying the efficiency with which thermal gradients can generate transverse spin currents. We accomplish this by comparing the spin Nernst magneto-thermopower to the spin Hall magnesistance for bilayers of Bi$_2$Se$_3$/CoFeB. We find that Bi$_2$Se$_3$ does generate substantial thermally-driven spin currents. A lower bound for the ratio of spin current to thermal gradient is $J_s/\nabla_x T$ = (4.9 $\pm$ 0.9) $\times$ 10$^{6}$ ($\hbar/2e$) A m$^{-2}$ / K $μ$m$^{-1}$, and a lower bound for the magnitude of the spin Nernst ratio is $-$0.61 $\pm$ 0.11. The spin Nernst ratio for Bi$_2$Se$_3$ is the largest among all materials measured to date, 2-3 times larger compared to previous measurements for the heavy metals Pt and W.
