Direct Observation of Macroscopic Charge Quantization
P Lafarge, H Pothier, Edwin R. Williams, D Esteve, C Urbina, Michel H. Devoret
The circuit formed by a nanoscale tunnel junction in series with a capacitance and a voltage source is the building block of most multi-junction circuits of single electronics. The state of this single electron box is entirely determined by the number n of extra electrons on the intermediate island electrode between the junction and the capacitance. We have fabricated such a system and measured the charge on the junction capacitance, which is directly related to the average value of n, as a function of the bias voltage using a Fulton-Dolan electrometer. At low temperature, the junction charge followed by e-periodic sawtooth function expected from the theory of macroscopic charge quantization. Strikingly, e-periodic variations were also observed when the box was superconducting. The thermal rounding of the sawtooth function is well explained by a simple model, except at the lowest temperatures.
Journal of Physics B-Atomic Molecular and Optical Physics
charge quantization, Coulomb blockade, single electron tunneling
, Pothier, H.
, Williams, E.
, Esteve, D.
, Urbina, C.
and Devoret, M.
Direct Observation of Macroscopic Charge Quantization, Journal of Physics B-Atomic Molecular and Optical Physics
(Accessed June 6, 2023)