Department of Physics, Yale University, New Haven, Connecticut 06520, USA.
Dahlem Center for Complex Quantum Systems and Fachbereich Physik, Freie Universität Berlin, 14195 Berlin, Germany.
Phys Rev Lett. 2023 May 26;130(21):216002. doi: 10.1103/PhysRevLett.130.216002.
We evaluate the differential conductance measured in an STM setting at arbitrary electron transmission between STM tip and a 2D superconductor with arbitrary gap structure. Our analytical scattering theory accounts for Andreev reflections, which become prominent at larger transmissions. We show that this provides complementary information about the superconducting gap structure beyond the tunneling density of states, strongly facilitating the ability to extract the gap symmetry and its relation to the underlying crystalline lattice. We use the developed theory to discuss recent experimental results on superconductivity in twisted bilayer graphene.
我们评估了在任意电子传输条件下，STM 针尖和二维超导体之间的微分电导测量值，其中超导体的能隙结构任意。我们的分析散射理论考虑了安德烈夫反射，当传输较大时，安德烈夫反射变得更加显著。我们表明，这提供了关于超导能隙结构的补充信息，超越了隧道态密度，极大地促进了提取能隙对称性及其与底层晶体格子关系的能力。我们使用所开发的理论来讨论扭曲双层石墨烯中超导性的最新实验结果。
