Efficient and flexible preparation of photonic NOON states in a superconducting system

TL;DR

This paper presents a practical, efficient method for generating high-fidelity photonic NOON states in superconducting systems using only classical control, avoiding nonlinear interactions and enabling broader applicability.

Contribution

The authors propose a novel protocol for NOON state preparation in superconducting cavities that requires only classical fields and fixed parameters, simplifying the process and enhancing practicality.

Findings

High fidelity NOON states achievable with current superconducting technology

Protocol robust against parameter fluctuations and decoherence

Flexible application without nonlinear interactions

Abstract

The NOON states play a critical role as physical resources in quantum information processing and quantum metrology, yet their preparation efficiency and applicability are often constrained by complicated operational procedures or the requirement for nonlinear interactions. In this paper, we propose an efficient protocol to generate the NOON states within two microwave cavities embedded in a superconducting system, assisted by an auxiliary five-level qudit. The state preparation is accomplished in three steps for an arbitrary photon number $N$ by adjusting only external classical fields, while keeping the qudit-cavity coupling strengths and the qudit level spacings fixed. Based on parameters accessible in superconducting systems, numerical simulations show that the protocol achieves relatively high fidelity for the NOON states preparation even in the presence of parameter fluctuations and decoherence effects. Thus, this protocol may provide a practical approach for preparing the NOON states with current technology. Notably, since nonlinear interactions are not required, the protocol is flexible and has the potential to be applied across various physical systems.