Superconducting tunable flux qubit with direct readout scheme

TL;DR

This paper introduces a simple, efficient readout scheme for a tunable flux qubit using a double SQUID with an extra Josephson junction, demonstrating preliminary experimental feasibility at liquid helium temperatures.

Contribution

The paper presents a novel, straightforward readout method for a tunable flux qubit based on a double SQUID with an additional Josephson junction, tested experimentally.

Findings

Feasibility of the readout scheme demonstrated

Preliminary tests show effective qubit state detection

Scheme operates efficiently at liquid helium temperature

Abstract

We describe a simple and efficient scheme for the readout of a tunable flux qubit, and present preliminary experimental tests for the preparation, manipulation and final readout of the qubit state, performed in incoherent regime at liquid Helium temperature. The tunable flux qubit is realized by a double SQUID with an extra Josephson junction inserted in the large superconducting loop, and the readout is performed by applying a current ramp to the junction and recording the value for which there is a voltage response, depending on the qubit state. This preliminary work indicates the feasibility and efficiency of the scheme.