Non-Demolition Dispersive Measurement of a Superconducting Qubit with a Microstrip SQUID Amplifier

TL;DR

This paper demonstrates that a superconducting qubit can be measured in a single-shot non-demolition manner using a microstrip SQUID amplifier, considering Johnson noise, with specific photon and mutual inductance conditions.

Contribution

It introduces a method for single-shot non-demolition measurement of superconducting qubits using a microstrip SQUID amplifier, including noise analysis and mutual inductance requirements.

Findings

Single-shot non-demolition measurement feasible with six photons.

Derived mutual inductance expression for phase qubit measurement.

Johnson noise impact considered in measurement analysis.

Abstract

We have studied the possibility of a single-shot non-demolition measurement of a superconducting qubit using a microstrip SQUID amplifier (MSA). The Johnson noise generated by all resistors in the MSA is taken into consideration. We show that a single-shot non-demolition measurement is possible with six photons in the measurement resonator. For a phase qubit inductively coupled to a measurement resonator we have obtained the expression for the mutual inductance required for measurement of the qubit state.