论文标题
拓扑绝缘子纳米纤维约瑟夫森连接：传输特性中尺寸效应的证据
Topological insulator nanoribbon Josephson junctions: evidence for size effect in transport properties
论文作者
论文摘要
我们已经使用BI $ _2 $ SE $ _3 $纳米式，由无催化剂的物理蒸气沉积生长，用Al超导电极制造高质量的Josephson交界处。在我们的设备中，我们观察到通过降低连接的宽度来显着减少约瑟夫森临界电流密度$ j_c $，在我们的情况下，这对应于纳米骨的宽度。由于拓扑表面状态延伸到纳米替比的整个周长上，因此与它们相关的超导转运是通过纳米替比的顶部和底部表面的模式携带的。我们表明，$ J_C $减少作为纳米骨宽度的函数，可以通过假设在我们通过几何考虑来得出的情况下，只有在顶部表面上传播的模式才会有助于约瑟夫森的运输。这一发现与拓扑量子电路方案非常相关，因为它表明约瑟夫森电流主要由拓扑表面状态携带。
We have used Bi$_2$Se$_3$ nanoribbons, grown by catalyst-free Physical Vapor Deposition to fabricate high quality Josephson junctions with Al superconducting electrodes. In our devices we observe a pronounced reduction of the Josephson critical current density $J_c$ by reducing the width of the junction, which in our case corresponds to the width of the nanoribbon. Because the topological surface states extend over the entire circumference of the nanoribbon, the superconducting transport associated to them is carried by modes on both the top and bottom surfaces of the nanoribbon. We show that the $J_c$ reduction as a function of the nanoribbons width can be accounted for by assuming that only the modes travelling on the top surface contribute to the Josephson transport as we derive by geometrical consideration. This finding is of a great relevance for topological quantum circuitry schemes, since it indicates that the Josephson current is mainly carried by the topological surface states.
