Optical Memory for Arbitrary Perfect Poincar\'e States in an Atomic Ensemble

TL;DR

This paper demonstrates the experimental storage of arbitrary perfect Poincaré states with high fidelity using perfect optical vortices, enhancing the capacity for complex quantum and classical information encoding.

Contribution

It introduces a method to store perfect Poincaré states with arbitrary OAM in an atomic ensemble, overcoming size and interaction challenges associated with Laguerre Gaussian beams.

Findings

Stored 121 arbitrary Poincaré states with high fidelity

Achieved robust storage of complex spin and orbital angular momentum states

Enhanced potential for optical communication and quantum networks

Abstract

Inherent spin angular momentum (SAM) and orbital angular momentum (OAM) which manifest as polarization and spatial degrees of freedom (DOF) of photons, hold a promise of large capability for applications in classical and quantum information processing. To enable these photonic spin and orbital dynamic properties strongly coupled with each other, Poincar\'{e} states have been proposed and offer advantages in data multiplexing, information encryption, precision metrology, and quantum memory. However, since the transverse size of Laguerre Gaussian beams strongly depends on their topological charge numbers $\left| l \right|$, it is difficult to store asymmetric Poincar\'{e} states due to the significantly different light-matter interaction for distinct spatial modes. Here, we experimentally realize the storage of perfect Poincar\'{e} states with arbitrary OAM quanta using the perfect optical vortex, in which 121 arbitrarily-selected perfect Poincar\'{e} states have been stored with high fidelity. The reported work has great prospects in optical communication and quantum networks for dramatically increased encoding flexibility of information.