Charging effects in the inductively shunted Josephson junction

TL;DR

This paper investigates how inductive shunting in Josephson junctions affects charge quantization, revealing that high-frequency responses become similar for large inductances, enabling observation of charging effects despite charge noise.

Contribution

It demonstrates that inductively shunted Josephson junctions exhibit high-frequency responses similar to capacitive shunts at large inductance, offering new ways to observe charge effects.

Findings

High-frequency responses of inductively and capacitively shunted junctions converge at large L.

Inductive shunting can reveal charge effects without charge noise interference.

Energy spectra differ significantly, but dynamic responses become similar at high frequencies.

Abstract

The choice of impedance used to shunt a Josephson junction determines if the charge transferred through the circuit is quantized: a capacitive shunt renders the charge discrete, whereas an inductive shunt leads to continuous charge. This discrepancy leads to a paradox in the limit of large inductances L. We show that while the energy spectra of the capacitively and inductively shunted junction are vastly different, their high-frequency responses become identical for large L. Inductive shunting thus opens the possibility to observe charging effects unimpeded by charge noise.