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arXiv · 2211.11389

Junctions and superconducting symmetry in twisted bilayer graphene

Héctor Sainz-Cruz·Pierre A. Pantaleón·Vo Tien Phong·Alejandro Jimeno-Pozo·Francisco Guinea
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Abstract

Junctions provide a wealth of information on the symmetry of the order parameter of superconductors. We analyze junctions between a scanning tunneling microscope (STM) tip and superconducting twisted bilayer graphene (TBG) and TBG Josephson junctions (JJs). We compare superconducting phases that are even or odd under valley exchange (s- or f-wave). The critical current in mixed (s- and f-) JJs strongly depends on the angle between the junction and the lattice. In STM-TBG junctions, due to Andreev reflection, f-wave leads to a prominent peak in subgap conductance, as seen in experiments.

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Héctor Sainz-Cruz, Pierre A. Pantaleón, Vo Tien Phong, Alejandro Jimeno-Pozo, Francisco Guinea. 2022-11-21. Junctions and superconducting symmetry in twisted bilayer graphene. https://doi.org/10.1103/physrevlett.131.016003

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