Superconducting Diode Effect in Two-dimensional Topological Insulator Edges and Josephson Junctions

<p>The superconducting diode effect -- the dependence of critical current on its direction -- can arise from the simultaneous breaking of inversion and time-reversal symmetry in a superconductor and has gained interest for its potential applications in superconducting electronics. In this dataset, we study the effect in a two-dimensional topological insulator (2D TI) in both a uniform geometry as well as in a long Josephson junction. We show that in the presence of Zeeman fields, a circulating edge current enables a large non-reciprocity of the critical current. We find a maximum diode efficiency 1 for the uniform 2D TI and (√2 − 1)<sup>2</sup> ≈ 0.17 for the long Josephson junction.</p>

<p>The code in this dataset uses the Kwant package for python to calculate the energy eigenvalues and eigenstates of models of a 2D TI ribbon and a 2D TI Josephson junction. Using the code provided in this dataset, one can calculate & plot the band structures, probability densities, and critical current vs. Zeeman field for the 2D TI ribbon, and calculate & plot the energy vs. phase, ground state energy vs. phase, and Josephson current vs. phase for the 2D TI Josephson junction. One can also calculate the Josephson diode efficiency of a long Josephson junction using its piece-wise linear single-edge current under various Zeeman fields.</p>