Related Experiment Video
Updated: Oct 14, 2025

Gradient Echo Quantum Memory in Warm Atomic Vapor
Published on: November 11, 2013
Measurement-Device-Independent Verification of a Quantum Memory
Yong Yu1, Peng-Fei Sun1, Yu-Zhe Zhang1
1Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China; and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
Abstract:
In this Letter we report an experiment that verifies an atomic-ensemble quantum memory via a measurement-device-independent scheme. A single photon generated via Rydberg blockade in one atomic ensemble is stored in another atomic ensemble via electromagnetically induced transparency. After storage for a long duration, this photon is retrieved and interfered with a second photon to perform a joint Bell-state measurement (BSM). The quantum state for each photon is chosen based on a quantum random number generator, respectively, in each run. By evaluating correlations between the random states and BSM results, we certify that our memory is genuinely entanglement preserving.
Related Concept Videos
Uncertainty in Measurement: Reading Instruments
Understanding Memory
The Quantum-Mechanical Model of an Atom
System of Memory
Eyewitness Memory
One such error is memory distortion, which occurs because human memory does not function...

