Kerr nonlinearities and nonclassical states with superconducting qubits and nanomechanical resonators

TL;DR

This paper proposes a method to generate nonclassical superposition states in nanomechanical resonators using superconducting qubits and Kerr nonlinearities, with potential applications in high-precision measurements.

Contribution

It introduces a novel scheme to induce Kerr nonlinearities in nanomechanical resonators via superconducting qubits and external driving fields, enabling the creation of Yurke-Stoler states.

Findings

Successful theoretical proposal for generating superposition states

Analysis of dissipation effects on state fidelity and purity

Potential for high-precision measurement applications

Abstract

We propose the use of a superconducting charge qubit capacitively coupled to two resonant nanomechanical resonators to generate Yurke-Stoler states, i.e. quantum superpositions of pairs of distinguishable coherent states 180$^\circ$ out of phase with each other. This is achieved by effectively implementing Kerr nonlinearities induced through application of a strong external driving field in one of the resonators. A simple study of the effect of dissipation on our scheme is also presented, and lower bounds of fidelity and purity of the generated state are calculated. Our procedure to implement a Kerr nonlinearity in this system may be used for high precision measurements in nanomechanical resonators.