2025/12/15 by Park, Jeongsoo, Cheong, Sang-Wook, Xu, Xianghan
#FOS: Physical sciences #Superconductivity (cond-mat.supr-con)
paper · doi:10.48550/arxiv.2512.13601
We investigate nonreciprocal electrical transport in bulk single-crystalline Mo3Al2C, a material known to host crystallographic chirality, a polar charge-density-wave instability, and a superconducting transition near 8 K. Using AC transport measurements to analyze the first-harmonic and second-harmonic resistance responses, we observe a distinct nonreciprocal second-harmonic signal that is significantly enhanced near the boundary of the normal and superconducting phases. Phenomenologically, this response arises from direction-dependent coupling between the external magnetic field and the current-induced intrinsic magnetization within the chiral lattice. Furthermore, a persistent nonreciprocal response observed under perpendicular magnetic fields suggests a toroidal-induced effect linked to the electric polarization emerging from the charge-density-wave phase. These results demonstrate that bulk Mo3Al2C serves as an intrinsic platform for tunable nonreciprocal transport rooted in the interplay of chirality, polarity, and superconductivity.