Fractional-flux Little-Parks resistance oscillations in disordered superconducting Au0.7In0.3 cylinders

The resistance of disordered superconducting Au0.7In0.3 cylindrical lms was measured as a function of applied magnetic field. In the high-temperature part of the superconducting transition regime, the resistance oscillated wi th a period of h/2e in units of the enclosed magnetic flux. However, at low er temperatures, the resistance peaks split. We argue that this splitting i s due to the emergence of an oscillation with a period of h/4e, half of the flux quantum for paired electrons. The possible physical origin of the h/4 e resistance oscillation is discussed in the context of new minima in the f ree energy of a disordered superconducting cylinder.