论文标题
超导体中的量子干扰 - $ {\ mathrm {mnbi}} _ {2} {\ mathrm {te}} _ {4} $ - 超导体Josephson Junction
Quantum interference in a superconductor-${\mathrm{MnBi}}_{2}{\mathrm{Te}}_{4}$-superconductor Josephson junction
论文作者
论文摘要
我们研究了约瑟夫森连接的运输特性，该连接由两个相同的$ s $ - 波超导体组成，这些超导体由均匀的$ {\ mathrm {\ mathrm {mnbi}} _ {2} {\ mathrm {te}}} _ {4} $（mbt）。使用递归绿色的函数方法，我们在存在垂直磁场的情况下计算超电流，并发现当MBT处于不同的磁性状态时，其量子干扰表现出不同的模式。在抗铁磁性状态下，MBT是支撑延伸的“铰链”超电流的轴线绝缘子，这会导致正弦曲线干扰模式随场强度而衰减。在铁磁状态下，MBT是Chern绝缘子，相反边缘的手性超电流不平衡会产生高度不对称的干扰模式。如果将MBT变成金属，因为Fermi水平被调用到传导带中，则由于均匀分布的散装大量超电流，干扰表现出Fraunhofer图案。我们的工作揭开了一个有力的指标，可以识别MBT中的不同阶段，并且可以通过实验直接验证。
We study the transport properties of a Josephson junction consisting of two identical $s$-wave superconductors separated by an even-layer ${\mathrm{MnBi}}_{2}{\mathrm{Te}}_{4}$ (MBT). Using recursive Green's function method, we calculate the supercurrent in the presence of a perpendicular magnetic field and find that its quantum interference exhibits distinct patterns when the MBT is in different magnetic states. In the antiferromagnetic state, the MBT is an axion insulator supporting an extended "hinge" supercurrent, which leads to a sinusoidal interference pattern decaying with the field strength. In the ferromagnetic state, the MBT is a Chern insulator and the unbalanced chiral supercurrents on opposite edges give rise to a highly asymmetric interference pattern. If the MBT turns into a metal as the Fermi level is tuned into the conduction band, the interference exhibits a Fraunhofer pattern due to the uniformly distributed bulk supercurrent. Our work unravels a strong indicator to identify different phases in the MBT and can be verified directly by experiments.
