Optimizing Raman quantum memory with dynamic phase

doi:10.1007/s11432-022-3614-7

Optimizing Raman quantum memory with dynamic phase

2023-06-19

2

PRE

AI

DOI：10.1007/s11432-022-3614-7

Original

Original request for help

Save

Abstract

En 中文

Optical quantum memory is a key component of emerging quantum technologies and applications. One of the most promising protocols, far-off-resonant Raman memory, is still beset by its efficiency. Until now, the only effective method for enhancing its efficiency in experiments has been the intensity modulation method on the control field, while the experimental demonstrations still fail to meet the theoretical expectation. In this study, we experimentally demonstrate how to optimize the Raman quantum memory process using a new method called phase modulation; 52.7% total memory efficiency is realized by applying a phase modulation on the control field with a near-square intensity waveform of the control field, thereby resulting in an increase in efficiency of 13.3% compared to the best case of no phase modulation. Additionally, a hybrid method, combining the phase and intensity modulations, is demonstrated with 87.3% memory efficiency. Such high-efficiency results in 99.0% unconditional fidelity even at near single photon level. The unconditional fidelity is always higher than that of the intensity method as the input photon number of the signal increases and can still beat the nonclone limit, even at 128.1 photons/pulse. Our phase modulation method has great potential applications in quantum information processing due to the advantages of low experimental requirements but an additional degree of freedom and high performance, especially for the high speed and high photon number state manipulation.

Keywords:

quantum information

quantum optics

quantum communication

quantum memory

Raman scattering

Optimizing Raman quantum memory with dynamic phase

Abstract

Journal

Organization