Identifying magnetic Weyl semimetals through nonreciprocal thermoelectric transport of surface states

Magnetic Weyl semimetals (MWSM) that break time-reversal symmetry provide a unique platform for exploring the interplay between magnetism, electron correlations, and topological orders. However, unambiguously identifying a material as a MWSM remains challenging. In this study, we propose a nonreciprocal thermoelectric transport method for the detection of MWSM. By manipulating Fermi arc surface states, we induce asymmetry between the bands on opposite surfaces, leading to a nonlinear response and the emergence of the unidirectional Seebeck effect. Our theoretical calculations of the thermoelectric coefficients for a minimal MWSM model reveal that the nonreciprocal signals are directly influenced by the Fermi arc discrepancy, making them promising transport measurements for identifying MWSM and probing the Fermi arc structures after surface state manipulation.