Current Induced Time-Reversal Symmetry Breaking in Kagome Superconductor CsV3Sb5

In recent years, the quasi-two-dimensional layered Kagome metals AV₃Sb₅ (A = K, Rb, Cs) have garnered significant attention due to their multiple exotic electronic states and rich phase diagram. With the coexistence of various charge order states and multigap superconductivity, the AV₃Sb₅ family presents a novel platform for exploring unconventional superconductivity and exotic pairing mechanisms. Notably, time-reversal symmetry breaking has been observed in the superconducting states of these non-magnetic materials, suggesting the presence of chiral superconductivity.
In this work, we report the observation of current-modulated magnetoresistance hysteresis below the superconducting transition temperature in the Kagome superconductor CsV₃Sb₅. This hysteresis is confined to the superconducting state and vanishes when superconductivity is fully suppressed, directly linking time-reversal symmetry breaking to the superconducting order in CsV₃Sb₅. Additionally, a magnetic field-driven superconducting diode effect is observed, suggesting chiral superconducting domains as a possible mechanism for the magnetoresistance hysteresis. Our findings position CsV₃Sb₅ as a promising platform for exploring nontrivial physical phenomena, including unconventional pairing mechanisms and topological superconductivity.