Fig. 1.

Supercurrent diode effect in a Rashba superconductor under in-plane magnetic field B and external current source J. (A and C) Device plots with circles denoting normal state Fermi surfaces, and (B and D) schematic phase diagrams in the B–J plane. When $\mathit{B}\parallel \mathit{J}$ in A, the phase diagram in B is symmetric with respect to both B and J axes. And, when $\mathit{B}\perp \mathit{J}$ in C, the phase diagram in D is skewed, indicating nonreciprocal critical current $J_c^{+}\ne J_c^{-}$ and polarity-dependent critical field $B_c^{+}\ne B_c^{-}$.