The correlation of the number and the phase uncertainties in the loop-type single-electron tunneling device

The electric and the magnetic transport properties of the loop-type Al/Al 2 O 3 /Al single-electron tunneling device were studied. Even for the sample with charging energy about one order of magnitude greater than the Josephson coupling energy, the magnetoresistance showed h /2 e -oscillation at low bias voltage, attributed to the phase-coherent pair tunneling. The behavior of the magnetoresistance depends on the gate voltage, showing large and noiseless oscillations with the even number of excess charges but small and noisy oscillations with the odd number of excess charges in the metal islands.