We consider a one-dimensional chain consisting of an interacting area coupled to non-interacting leads. Within the area, interaction is mediated by a local on-site repulsion. Using real time evolution within the Density Matrix Renormalisation Group (DMRG) scheme, we study the dynamics of wave packets in this two-terminal transport setup. In contrast to previous works, where excitations were created by adding potentials to the Hamiltonian, we explicitly create left moving single particle excitations in the right lead as the starting condition. Our simulations show that such a transport setup allows for a clear detection of spin-charge separation using time-resolved spin-polarised density measurements.
We investigate the quantum transport through Kondo impurity assuming both a large number of orbital channels $\mathcal K$$\gg $$1$ for the itinerant electrons and a semi-classical spin ${\cal S}$ $\gg $ $1$ for the impurity. The non-Fermi liquid regime of the Kondo problem is achieved in the overscreened sector $\mathcal K>2\mathcal{S}$. We show that there exist two distinct semiclassical regimes for the quantum transport through impurity: i) $\mathcal K$ $\gg$ $\mathcal S$ $\gg$ $1$, differential conductance vanishes and ii) $\mathcal S$$/$$\mathcal K{=}\mathcal C$ with $ 0$$<$$\mathcal C$$<$…
Topological delocalization and tuning of surface channel separation in Bi2Se2Te Topological Insulator Thin films
三维拓扑绝缘体（TI）的表面态具有抗后向散射的拓扑保护作用。然而，体电子对输运数据的贡献是表面拓扑保护的一个障碍。我们报告的化学势的调谐在大块的Bi 2 Se 2 Te TI薄膜，钉扎它附近的中心的散装带隙，从而抑制散装载流子。这些薄膜的温度依赖性电阻显示出低至50K的活化行为，随后在较低温度下发生金属转变，这是TI表面态稳健性的标志。用二维弱反定域化现象解释了拓扑保护和表面支配输运的表现。在这项工作中，我们进一步探讨了TI中的表面到体耦合的效果，这是由参与运输的有效导电表面通道的数量捕获的。单个导电通道的存在表明强的表面到体耦合，这对纯拓扑输运是有害的。我们证明了在薄膜的相对表面上的拓扑表面态的解耦，从而抑制了体输运。我们的研究结果提供了一个更深入的了解，随着拓扑输运行为和它们各自的可调性的表面到体耦合。
