Probing superconducting gap structure and time reversal symmetry state of SrPd2As2 and BaPd2As2 using muon spin relaxation and rotation

Recent observations of time reversal symmetry breaking in s-wave BCS superconductors have generated considerable interests in muon spin relaxation and rotation (µSR) investigations of s-wave superconductors. SrPd2As2, and BaPd2As2 are two such superconductors which exhibit superconductivity below the transition temperature Tc = 0.92 K and 3.85 K, respectively. The electrical resistivity and heat capacity measurements reveal electron-phonon mediated weak coupling type-II superconductivity possibly with an anisotropic s-wave gap. It would be of interest to further investigate the superconducting properties of SrPd2As2, and BaPd2As2 using µSR measurements to probe the superconducting gap structure and the time reversal symmetry state. We therefore propose to carry out µSR study on these compounds using the MuSR spectrometer.