Quantum estimation via parametric amplification in circuit QED arrays

TL;DR

This paper introduces a quantum estimation scheme using parametric amplification in circuit QED, optimizing initial states and employing arrays of resonators to enhance measurement precision for quantum metrology.

Contribution

It presents a novel method combining parametric amplification and resonator arrays in circuit QED for improved quantum estimation.

Findings

Optimized initial parameters maximize Quantum Fisher Information.

Array of resonators enables multiple independent measurements.

Potential application in quantum metrology with high precision.

Abstract

We propose a scheme for quantum estimation by means of parametric amplification in circuit Quantum Electrodynamics. The modulation of a SQUID interrupting a superconducting waveguide transforms an initial thermal two-mode squeezed state in such a way that the new state is sensitive to the features of the parametric amplifier. We find the optimal initial parameters which maximize the Quantum Fisher Information. In order to achieve a large number of independent measurements we propose to use an array of non-interacting resonators. We show that the combination of both large QFI and large number of measurements enables -in principle- the use of this setup for Quantum Metrology applications.