Preparation of high fidelity entangled cat states with composite pulses

TL;DR

This paper presents a robust protocol for generating high-fidelity entangled cat states using composite pulses in Kerr-nonlinear resonators, enhancing stability against errors and decoherence.

Contribution

The authors introduce a novel composite pulse scheme that improves the fidelity and robustness of entangled cat state preparation in Kerr-resonator systems.

Findings

Protocol is insensitive to timing and detuning errors

Strong robustness to decoherence demonstrated

Numerical simulations confirm high fidelity under realistic conditions

Abstract

We propose a protocol for the preparation of high-fidelity entangled cat states with composite pulses. The physical model contains two Kerr-nonlinear resonators and a cavity. By properly designing the parameters, each Kerr-nonlinear resonator is confined in the cat-state subspace and the entangled cat states can be generated efficiently. We introduce composite two-photon drives with multiple amplitudes and frequencies to improve the fidelity of the entangled cat states in the presence of parameter errors. The performance of the protocol is estimated by taking into account the parametric errors and decoherence. Numerical simulation results show that the protocol is insensitive to timing error and detuning error, and has strong robustness to decoherence. We hope the protocol may provide a method for preparing stable entangled cat states.