论文标题
通过电导测量来探测扩散多性约瑟夫森接线设备的拓扑带结构
Probing the topological band structure of diffusive multiterminal Josephson junction devices with conductance measurements
论文作者
论文摘要
与两个超导体分散的干净的普通金属中，安德里夫（Andreev）结合状态的能量在超导阶段的差异$ δϕ $与超导体之间的差异与一维晶体分散的电子能量与晶体动量$ k $ k $ k $相同。带有$ n $超导体的普通金属映射到$ n-1 $尺寸晶体，每个维度对应于一对超级导体之间的相位差$ ϕ_i $。已经提出，所得的谱带结构是相位差的函数$ \ {δϕ_i \} $具有拓扑性质，间隙区域的特征是不同的Chern数字被不同的区域隔开，其中Quasiparticle Spectrum Spectrum spectrum的间隙关闭。还可以预测，与多个超导体接触的扩散正常金属，也预测了与$ \ {δϕ_i \} $的类似复合演化。在这里，我们表明，可以通过相对简单的电导测量直接探测该系统的费米能量状态密度的变化，从而可以快速表征能量谱。
The energy of an Andreev bound state in a clean normal metal in contact with two superconductors disperses with the difference $Δϕ$ in the superconducting phase between the superconductors in much the same way as the energies of electrons in a one-dimensional crystal disperse with the crystal momentum $k$ of the electrons. A normal metal with $n$ superconductors maps on to a $n-1$ dimensional crystal, each dimension corresponding to the phase difference $ϕ_i$ between a specific pair of superconductors. The resulting band structure as a function of the phase differences $\{Δϕ_i\}$ has been proposed to have a topological nature, with gapped regions characterized by different Chern numbers separated by regions where the gap in the quasiparticle spectrum closes. A similar complex evolution of the quasiparticle spectrum with $\{Δϕ_i\}$ has also been predicted for diffusive normal metals in contact with multiple superconductors. Here we show that the variation of the density of states at the Fermi energy of such a system can be directly probed by relatively simple conductance measurements, allowing rapid characterization of the energy spectrum.
