Investigating the Superconducting Order Parameter of LaNiGa₂

LaNiGa₂ is a topological, centrosymmetric superconductor with orthorhombic crystal structure. Its non-symmorphic symmetries give rise to its unconventional superconductivity and topologically-protected order parameter. Previous μSR measurements indicate that it breaks time-reversal symmetry due to the onset of spontaneous magnetic fields as it transitions into the superconducting phase, implying the possibility of spin-triplet pairing states. However, previous London penetration depth measurements agree with isotropic s-wave behavior down to 50 mK. One hint of non-BCS behavior comes from specific heat. Fits to a BCS form are successful over limited temperature ranges, but not over the entire range from 300 mK to T_c. We present two measurements that further probe the symmetry and topological behavior of the order parameter: extending specific heat data to lower temperatures, and testing the behavior of T_c under uniaxial pressure.