Mesoscopic Shelving Readout of Superconducting Qubits in Circuit QED

TL;DR

This paper introduces a novel method for high-fidelity, single-shot, quantum nondemolition readout of superconducting qubits using mesoscopic cavity fields, inspired by ion shelving techniques.

Contribution

It proposes a new measurement scheme that correlates qubit states with cavity field states, enhancing readout fidelity in circuit QED systems.

Findings

Achieves efficient single-shot QND-like readout of superconducting qubits.

Demonstrates generation of large cavity coherent fields for one qubit state.

Potential for adapting to various superconducting qubit designs.

Abstract

We present a method for measuring the internal state of a superconducting qubit inside an on-chip microwave resonator. We show that one qubit state can be associated with the generation of an increasingly large cavity coherent field, while the other remains associated with the vacuum. By measuring the outgoing resonator field with conventional devices, an efficient single-shot QND-like qubit readout can be achieved, enabling a high-fidelity measurement in the spirit of the electron-shelving technique for trapped ions. We expect that the proposed ideas can be adapted to different superconducting qubit designs and contribute to the further improvement of qubit readout fidelity.