films*

Symmetry plays an important role in superconductivity. In noncentrosymmetric superconductors, the pairing state might become a mixture of spin-singlet and spin-triplet components due to the anti-symmetric spin-orbit coupling (ASOC), which is “protected” by the lack of an inversion center. This mixing can further lead to two-gap physics. We investigated the transport properties of various La(Pt_xSi_1-x)₂ thin films grown by molecular beam epitaxy (MBE), where the inversion symmetry and spin-orbit coupling strength are tunable by varying the Pt concentration x. For certain x, magnetoresistance shows a two-step transition at finite temperatures below T_c, and the upper critical field is well described by a two-band model. Furthermore, the current-voltage characteristics, along with the differential resistance measurements, reveal a two-gap structure in magnetic fields up to 1 T. These observations indicate the multi-gap superconductivity in La(Pt_xSi_1-x)₂ films.