Efficient preparation of Dicke states

TL;DR

This paper introduces an efficient quantum algorithm for preparing Dicke states using mid-circuit measurement and feedback, achieving polylogarithmic depth and ancilla requirements, with practical implementation in cavity QED systems.

Contribution

The authors develop a novel algorithm that significantly improves the efficiency of Dicke state preparation in terms of depth and width, applicable to larger systems.

Findings

Achieves polylogarithmic depth and ancilla count for Dicke state preparation.

Utilizes only global measurements and rotations, simplifying implementation.

Can be implemented in cavity QED with minimal resources.

Abstract

We present an algorithm utilizing mid-circuit measurement and feedback that prepares Dicke states with polylogarithmically many ancillas and polylogarithmic depth. Our algorithm uses only global mid-circuit projective measurements and adaptively-chosen global rotations. This improves over prior work that was only efficient for Dicke states of low weight, or was not efficient in both depth and width. Our algorithm can also naturally be implemented in a cavity QED context using polylogarithmic time, zero ancillas, and atom-photon coupling scaling with the square root of the system size.