Temperature dependence of conduction noise of MgB2 superconductor

Temperature dependent behavior of conduction noise of MgB2 superconductor has been studied. The frequency spectrum of conduction noise shows 1/fα type of behavior, with α = 0.7–0.8. Temperature dependence of conduction noise is found to exhibit two peaks at ∼26 K and ∼38 K respectively. The peak at ∼38 K is attributed to movement of vortices and due to fluctuation in resistance from change of state from superconducting to normal state. The peak in the conduction noise at ∼26 K is ascribed to the movement of vortices due to enhanced thermally activated vortex hopping. The analysis of enhanced conduction noise in the low temperature region indicates the presence large density of fluctuators with activation energies around 0.048 eV.