论文标题
II型dirac半学nite $ _2 $中的接口超导性
Interface superconductivity in a type-II Dirac semimetal NiTe$_2$
论文作者
论文摘要
我们通过单个平面连接来调查电荷传输，否则$ _2 $ _2 $ dirac半学和正常的金铅。在Millikelvin温度下，我们观察到非荷兰$ DV/DI（V）$行为类似于Andreev反射，以超导体形式 - 正常的金属界面，而Nite $ _2 $ bumb仍然是非驾驶的。通过温度和磁场抑制效果，还支持了超导性的结论。就像CD $ _3 $的已知结果为$ _2 $ DIRAC半学，我们将这种行为与界面的超导性联系起来，这是由于Au-nite $ _2 $接口处的平坦频段组。由于平坦和拓扑表面状态密切相关，因此约瑟夫森电流通过原始的nite $ _2 $表面上的拓扑表面状态支持了扁平频段引起的超导性的主张。我们证明了明显的约瑟夫森二极管效应，这是由于平面磁场下nite $ _2 $的拓扑表面状态的动量移动而产生的。
We experimentally investigate charge transport through a single planar junction between a NiTe$_2$ Dirac semimetal and a normal gold lead. At millikelvin temperatures we observe non-Ohmic $dV/dI(V)$ behavior resembling Andreev reflection at a superconductor -- normal metal interface, while NiTe$_2$ bulk remains non-superconducting. The conclusion on superconductivity is also supported by suppression of the effect by temperature and magnetic field. In analogy with the known results for Cd$_3$As$_2$ Dirac semimetal, we connect this behavior with interfacial superconductivity due to the flat-band formation at the Au-NiTe$_2$ interface. Since the flat-band and topological surface states are closely connected, the claim on the flat-band-induced superconductivity is also supported by the Josephson current through the topological surface states on the pristine NiTe$_2$ surface. We demonstrate the pronounced Josephson diode effect, which results from the momentum shift of topological surface states of NiTe$_2$ under an in-plane magnetic field.
