Spin squeezing and Schr\"{o}dinger cat generation in atomic samples with Rydberg blockade

TL;DR

This paper proposes a method to generate spin-squeezed and Schrödinger cat-like states in atomic ensembles using Rydberg blockade, involving effective Jaynes-Cummings and J_x interactions, with strategies to optimize the evolution speed.

Contribution

It introduces a novel scheme combining Rydberg excitation and Raman coupling to produce non-classical states of collective atomic spins, including techniques to enhance the speed of state preparation.

Findings

Effective scheme for spin squeezing and cat state generation.

Adiabatic and dynamical evolution strategies analyzed.

Speed-up of state preparation via resonant laser fields.

Abstract

A scheme is proposed to prepare squeezed states and Schr\"{o}dinger cat-like states of the collective spin degrees of freedom associated with a pair of ground states in an atomic ensemble. The scheme uses an effective Jaynes-Cummings interaction which can be provided by excitation of the atoms to Rydberg states and an effective J_x interaction implemented by a resonant Raman coupling between the atomic ground states. Both dynamical evolution with a constant Hamiltonian and with adiabatic variation of the two interaction terms are studied. We show that by the application of further resonant laser fields, we can suppress non-adiabatic transfer under the time varying Hamiltonian and significantly speed up the evolution towards a maximally squeezed, J_z=0, collective spin state.