We report a comprehensive transverse-field SR study of Cu x TiSe 2 . The magnetic penetration depth was found to saturate at low temperature as expected in an s-wave superconductor. As x is increased we find that the superfluid density increases and the size of the superconducting gap, calculated from the temperature dependence of the superfluid density, is approaching the BCS value. However, for low values of x, the gap is smaller than the weak-coupling BCS prediction suggesting that two superconducting gaps are present in the sample.

We report measurements of the current noise generated by the optimally doped, x=0.15, Au-La2−xSrxCuO4 junctions. For high transmission junctions on (110) surface, we observed split zerobias conductance peak (ZBCP), accompanied by enhanced shot noise. We attribute the enhanced noise to the Cooper pair transport through the junction. The ZBCP disappears and the noise decreases to the one expected for the charge e with heating at temperatures well below Tc, and at voltages much smaller than the bulk superconducting gap, setting a new energy scale of 0.5 mV. We attribute this scale to the existence of an idxy or is order parameter at the sample surface.

We report a comprehensive TF-µSR study of CuxTiSe2. The magnetic penetration depth was found to saturate at low temperature as expected in an s-wave SC. As x is increased we find that the superfluid density increases and the size of the superconducting gap, calculated from the temperature dependence of the superfluid density, is approaching the BCS value. However, for low values of x, the gap is smaller than the weak-coupling BCS prediction suggesting that two superconducting gaps are present in the sample.