Efficient preparation of Dicke states

Understand

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.