Fully gapped superconductivity with preserved time-reversal symmetry in noncentrosymmetric LaPdIn

We report an investigation of the superconducting properties hexagonal noncentrosymmetric compound LaPdIn. Electrical resistivity, specific heat and ac susceptibility measurements demonstrate presence bulk superconductivity below $T_c$ = 1.6 K. The heat, together with penetration depth measured using transverse-field muon spin rotation tunnel diode oscillator based method, are well described by single gap $s$-wave superconductivity, a magnitude 1.8$k_BT_c$. From zero-field relaxation results no evidence is found for spontaneous emergence magnetic fields in state, indicating that time-reversal symmetry preserved. Band structure calculations reveal there relatively weak effect antisymmetric spin-orbit coupling on electronic bands near Fermi level, which consistent being negligible singlet-triplet mixing due to broken inversion symmetry. On other hand, isostructural LuPdIn LaPtIn do not exhibit down 0.4 K, may be these systems having smaller density states at level.