A Broadband DLCZ Quantum Memory in Room-Temperature Atoms

• Published in: arXiv.org
• Main Authors: Jian-Peng Dou, Ai-Lin, Yang, Mu-Yan, Du, Lao, Di, Gao, Jun, Lu-Feng, Qiao, Li, Hang, Xiao-Ling, Pang, Feng, Zhen, Tang, Hao, Xian-Min, Jin
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 24.09.2018
• Subjects: Bandwidths; Bell's inequality; Broadband; Coherence; Cross correlation; Photons; Physics - Optics; Physics - Quantum Physics; Quantum phenomena; Room temperature
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1704.06309

Quantum memory capable of stopping flying photons and storing their quantum coherence is essential for scalable quantum technologies. A room-temperature broadband quantum memory will enable the implementation of large-scale quantum systems for real-life applications. Due to either intrinsic high noises or short lifetime, it is still challenging to find a room-temperature broadband quantum memory beyond conceptual demonstration. Here, we present a far-off-resonance Duan-Lukin-Cirac-Zoller (FORD) protocol and demonstrate the broadband quantum memory in room-temperature atoms. We observe a low unconditional noise level of \(10^{-4}\) and a cross-correlation up to 28. A strong violation of Cauchy-Schwarz inequality indicates high-fidelity generation and preservation of non-classical correlation. Furthermore, the achieved cross-correlation in room-temperature atoms exceeds the key boundary of 6 above which quantum correlation is able to violate Bell's inequality. Our results open up the door to an entirely new realm of memory-enabled quantum applications at ambient conditions.