Anomalous angle dependence of superconducting diode effect in a mixed spin-orbit coupling system.

In noncentrosymmetric superconductors with strong spin-orbit coupling (SOC), an external magnetic field can induce the superconducting diode effect (SDE) characterized by the helical superconductivity. In this paper, we explore the intrinsic SDE in a superconductor with both Rashba and Dresselhaus SOCs and highlight the role of magnetic field direction in the nonreciprocal helical superconductivity. Numerical results reveal that the magnitude of the field-induced Cooper-pair momentum, which is relevant for the helical superconductivity, exhibits a strong anisotropy when the direction angle of the in-plane magnetic field is varied. This anisotropy, in turn, gives rise to a complex angle dependence of the SDE. Our results can be directly tested experimentally and pave the way for realizing SDE in mixed-SOC systems.