Certification of high-dimensional entanglement and Einstein-Podolsky-Rosen steering with cold atomic quantum memory

TL;DR

This paper demonstrates the generation, storage, and certification of high-dimensional entangled states in a cold atomic quantum memory, using entropic EPR-steering inequalities to verify entanglement in noisy conditions.

Contribution

It introduces an experimental method to certify high-dimensional entanglement and EPR-steering in a quantum memory system using entropic inequalities, showing robustness against noise.

Findings

Achieved genuine violation of 1.06±0.15 bits of EPR-steering inequality.

Certified entanglement of formation of at least 0.70±0.15 ebits.

Demonstrated the effectiveness of entropic witnesses for noisy and lossy quantum states.

Abstract

The advent of structured, high-dimensional entangled states brings new possibilities for quantum imaging, information processing and quantum key distribution. We experimentally generate and characterize a spatially entangled state stored in a quantum memory system, using entropic EPR-steering inequality, yielding genuine violation of $1.06\pm0.15$ bits and certifying entanglement of formation of at least $0.70\pm0.15$ ebits. The supremacy of the entropic witness is demonstrated for a wide class of experimentally available states, giving prospects for EPR-steering applications in noisy systems or with lossy quantum channels.