Superconducting diode effect in the Weyl semimetal Td-MoTe2 that has a surface modulated by Al nanoparticles

Abstract

Breaking both inversion and time reversal symmetry could lead to nonreciprocal current transport in a superconductor, where current is dissipationless in one direction and dissipative in the opposite direction, which is called the superconducting diode effect (SDE). We studied SDE in the type-II Weyl semimetal T_d-MoTe₂ that is covered with Al nanoparticles. Asymmetric V–I characteristics have been measured under a magnetic field. The superconducting diode efficiency reaches as high as 30%. Besides SDE under the out-of-plane field, nonreciprocal supercurrent transport under the in-plane field has been observed. Intriguingly, the maximum SDE occurs in the in-plane field parallel to the current direction, which contradicts present theories. Our work provides further understanding of the origins of the SDE.