# Temporal Wheeler's delayed-Choice Experiment based on Cold Atomic Quantum Memory

## TL;DR

This paper demonstrates a Wheeler's delayed-choice experiment using cold atomic quantum memory, revealing wave-particle complementarity at the single-photon level through light-matter interactions.

## Contribution

It introduces a novel implementation of Wheeler's delayed-choice experiment utilizing atomic memory as a memory beam splitter, exploring wave-particle duality in light-matter systems.

## Key findings

- Observation of morphing between particle and wave behavior.
- Control of quantum behavior via memory efficiency and storage time.
- Evidence of wave-particle complementarity in atomic memory interface.

## Abstract

Nowadays the most intriguing features of wave particle complementarity of single photon is exemplified by the famous Wheeler's delayed choice experiment in linear optics, nuclear magnetic resonance and integrated photonic device systems. Studying the wave particle behavior in light and matter interaction at single photon level is challenging and interesting, which gives how single photons complement in light and matter interaction. Here, we demonstrate a Wheeler's delayed choice experiment in an interface of light and atomic memory, in which the cold atomic memory makes the heralded single photon divided into a superposition of atomic collective excitation and leaked pulse, thus acting as memory beam splitters. We observe the morphing behavior between particle and wave of a heralded single photon by changing the relative proportion of quantum random number generator, the second memory efficiency, and the relative storage time of two memories. The reported results exhibit the complementarity behavior of single photon under the interface of light atom interaction.