Direct measurements of tunable Josephson plasma resonance in the L-SET

TL;DR

This paper reports direct measurements of the tunable Josephson plasma resonance in the L-SET, analyzing phase dynamics and demonstrating charge sensitivity comparable to the best rf-SETs.

Contribution

It provides the first direct measurements of Josephson plasma resonance in the L-SET and discusses its operation and charge sensitivity.

Findings

Resonance can be tuned by magnetic flux or gate charge.

Charge sensitivity comparable to rf-SETs achieved.

Analysis includes phase particle model and circuit simulations.

Abstract

Phase dynamics has been measured in a driven mesoscopic Josephson oscillator where the resonance is tuned either by magnetic flux or by gate charge modulation of the Josephson inductance. Phenomena are analyzed in terms of a "phase particle picture", and by numerical circuit simulations. An analogy to switching of a DC-biased junction into voltage state is discussed. Operation principle of the recently demonstrated Inductive Single-Electron transistor (L-SET) based on the driven oscillator is reviewed. The obtained charge sensitivity implies that a performance comparable to the best rf-SETs has already been reached with the novel device.