SciPost Phys. 10, 093 (2021) ·
published 29 April 2021
Charge quantization, or the absence thereof, is a central theme in quantum
circuit theory, with dramatic consequences for the predicted circuit dynamics.
Very recently, the question of whether or not charge should actually be
described as quantized has enjoyed renewed widespread interest, with however
seemingly contradictory propositions. Here, we intend to reconcile these
different approaches, by arguing that ultimately, charge quantization is not an
intrinsic system property, but instead depends on the spatial resolution of the
charge detector. We show that the latter can be directly probed by unique
geometric signatures in the correlations of the supercurrent. We illustrate
these findings at the example of Josephson junction arrays in the superinductor
regime, where the transported charge appears to be continuous. Finally, we
comment on potential consequences of charge quantization beyond superconducting
Dr Riwar: "I warmly thank the referee for..."
in Submissions | report on Charge quantization and detector resolution