Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Generation of subnatural-linewidth biphotons from a hot rubidium atomic vapor cell

Yanhong Xiao, Chi Shu, Lingbang Zhu, Peng Chen, Shengwang Du, Xianxin Guo, Heejeong Jeong

Published Jan 1, 2017• 0 citations
OpenAlex

Abstract

We report the generation of narrowband entangled photon pairs (biphotons) from a hot atomic vapor cell. Making use of backward spontaneous four-wave mixing with electromagnetically induced transparency (EIT), we produced subnatural-linewidth (1.9 MHz < 6 MHz) biphotons from a Doppler-broadened (0.5 GHz) hot (63 C) paraffin-coated rubidium 87 vapor cell. The biphoton coherence time is controable and can be tuned up to 100 ns by EIT. The uncorrelated photons from resonance Raman scattering are suppressed by a spatially separated and tailored optical pumping beam. The spectral brightness is as high as 14,000 s−1MHz−1. As compared with the cold-atom experiment , the hot atomic vapour cell configuration is much simpler for operation and maintenance, and it is a continuous biphoton source. Our demonstration may lead to miniature narrowband biphoton sources based on atomic vapour cells for practical quantum applications and engineering.

Related papers

Subnatural-linewidth biphotons from a Doppler-broadened hot atomic vapour cell

Chi Shu, Peng Chen, Tsz-Kiu Aaron Chow +4 more

Abstract Entangled photon pairs, termed as biphotons, have been the benchmark tool for experimental quantum optics. The quantum-network protocols based on photon–atom interfaces have stimulated a great demand for single photons with bandwidth comparable to or narrower than the atomic natural linewidth. In the past decade, laser-cooled atoms have often been used for producing such biphotons, but the apparatus is too large and complicated for engineering. Here we report the generation of subnatural-linewidth (<6 MHz) biphotons from a Doppler-broadened (530 MHz) hot atomic vapour cell. We use on-resonance spontaneous four-wave mixing in a hot paraffin-coated 87Rb vapour cell at 63 °C to produce biphotons with controllable bandwidth (1.9–3.2 MHz) and coherence time (47–94 ns). Our backward phase-matching scheme with spatially separated optical pumping is the key to suppress uncorrelated photons from resonance fluorescence. The result may lead towards miniature narrowband biphoton sources.

arXiv:1602.08561•Nature Communications•Sep 23, 2016•118 citations

Bright narrowband biphoton generation from a hot rubidium atomic vapor cell

Lingbang Zhu, Xianxin Guo, Chi Shu +2 more

We demonstrate the generation of high-quality narrowband biphotons from a Doppler-broadened hot rubidium atomic vapor cell. Choosing a double-Λ atomic energy level scheme for optimizing both spontaneous four-wave mixing nonlinear parametric interaction and electromagnetically induced transparency (EIT), we achieve a biphoton spectral brightness as high as 14 000 s−1 MHz−1. Meanwhile, we apply a spatially tailored optical pumping beam for reduction of the Raman noise and obtain a violation of the Cauchy-Schwarz inequality by a factor of 1023.

Applied Physics Letters•Apr 17, 2017•46 citations

Enhanced spectral brightness of narrowband photon pair generation from a hot atomic vapor cell

Lingbang Zhu, Xianxin Guo, Chi Shu +2 more

We report the high-quality narrowband biphoton generation from a Doppler-broadened hot rubidium atomic vapor. Utilizing optimized energy scheme for both spontaneous four-wave mixing and electromagnetically induced transparency, we achieve a spectral brightness of 14,000 s−1MHz−1.

Nonlinear Optics•Jan 1, 2017•0 citations

Narrow linewidth photon pair generation from polarized warm atomic gas using hollow optical pumping

Taek Jeong, Han Seb Moon

Summary form only given. Entangled photon pair is key factor for realization of quantum communication, quantum information, etc. For long distance quantum communication, it is necessary to generate narrow band biphoton for interaction with atomic based quantum memory. In recent years, generation of time-frequency entangled photon pairs based on spontaneous four-wave mixing (SFWM) process in atomic ensemble have been reported [1-3]. Very recently, S. Chu et al. achieved generation of strongly correlated subnatural-linewidth biphoton from Doppler-broaden hot atomic ensemble [4]. The group used paraffin-coated87Rb vapour cell and separated optical pumping effect for reduce noise of fluorescence from resonant coupling field. In this paper, we performed experiment for subnatural-linewidth biphoton generation from hot atomic ensembles by using a hollow optical pumping field and regular vapour cell, which are not special coated cell.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•Jun 1, 2017•0 citations

Proposed narrowband biphoton generation from an ensemble of solid-state quantum emitters

Heejeong Jeong, Shengwang Du, Na Young Kim

We explore a mechanism for producing time-frequency entangled photon pairs (termed a biphoton) from an ensemble of atom-like solid-state quantum emitters. Four distinct energy levels of the solid-state system render four spin-conserving optical transitions as observed in color centers. This feature opens up the possibility to generate a four-wave mixing biphoton based on an electromagnetic induced transparency (EIT) for long-coherence quantum communication as demonstrated in cold atomic systems. We propose a narrow EIT window below a lifetime-limited linewidth of a SiV− in diamond, assuming a few hundred MHz. Consequently, the EIT-induced narrowband guarantees biphoton coherence time to be at least a few tens of a nanosecond without a cavity. Assessing the criteria of solid-state parameters applicable to the existing biphoton model from cold atoms will accelerate solid-state biphoton source research. This study shows that a realization of negligible ground state dephasing of a solid-state sample will be a crucial step toward a solid-state biphoton generation for more than a 100 ns time scale with a subnatural atomic linewidth of a few MHz.

Journal of the Optical Society of America B•Feb 12, 2019•5 citations

Generation of sub-MHz and spectrally-bright biphotons from hot atomic vapors with a phase mismatch-free scheme

Chia-Yu Hsu, Yusheng Wang, Jia-Mou Chen +11 more

We utilized the all-copropagating scheme, which maintains the phase-match condition, in the spontaneous four-wave mixing (SFWM) process to generate biphotons from a hot atomic vapor. The linewidth and spectral brightness of our biphotons surpass those of the biphotons produced with the hot-atom SFWM in the previous works. Moreover, the generation rate of the sub-MHz biphoton source in this work can also compete with those of the sub-MHz biphoton sources of the cold-atom SFWM or cavity-assisted spontaneous parametric down conversion. Here, the biphoton linewidth is tunable for an order of magnitude. As we tuned the linewidth to 610 kHz, the generation rate per linewidth is 1,500 pairs/(s·MHz) and the maximum two-photon correlation function, g s , a s ( 2 ) , of the biphotons is 42. This g s , a s ( 2 ) violates the Cauchy-Schwarz inequality for classical light by 440 folds, and demonstrates that the biphotons have a high purity. By increasing the pump power by 16 folds, we further enhanced the generation rate per linewidth to 2.3×10 4 pairs/(s·MHz), while the maximum g s , a s ( 2 ) became 6.7. In addition, we are able to tune the linewidth down to 290±20 kHz. This is the narrowest linewidth to date among all single-mode biphoton sources of room-temperature and hot media.

arXiv:2012.04893•Optics Express•Jan 22, 2021•34 citations
We report the generation of narrowband entangled photon pairs (biphotons) from a hot atomic vapor cell. Making use of backward spontaneous four-wave mixing with electromagnetically induced transparency (EIT), we produced subnatural-linewidth (1.9 MHz < 6 MHz) biphotons from a Doppler-broadened (0.5 GHz) hot (63 C) paraffin-coated rubidium 87 vapor cell. The biphoton coherence time is controable and can be tuned up to 100 ns by EIT. The uncorrelated photons from resonance Raman scattering are suppressed by a spatially separated and tailored optical pumping beam. The spectral brightness is as high as 14,000 s−1MHz−1. As compared with the cold-atom experiment , the hot atomic vapour cell configuration is much simpler for operation and maintenance, and it is a continuous biphoton source. Our demonstration may lead to miniature narrowband biphoton sources based on atomic vapour cells for practical quantum applications and engineering.
Abstract Entangled photon pairs, termed as biphotons, have been the benchmark tool for experimental quantum optics. The quantum-network protocols based on photon–atom interfaces have stimulated a great demand for single photons with bandwidth comparable to or narrower than the atomic natural linewidth. In the past decade, laser-cooled atoms have often been used for producing such biphotons, but the apparatus is too large and complicated for engineering. Here we report the generation of subnatural-linewidth (<6 MHz) biphotons from a Doppler-broadened (530 MHz) hot atomic vapour cell. We use on-resonance spontaneous four-wave mixing in a hot paraffin-coated 87Rb vapour cell at 63 °C to produce biphotons with controllable bandwidth (1.9–3.2 MHz) and coherence time (47–94 ns). Our backward phase-matching scheme with spatially separated optical pumping is the key to suppress uncorrelated photons from resonance fluorescence. The result may lead towards miniature narrowband biphoton sources.
We demonstrate the generation of high-quality narrowband biphotons from a Doppler-broadened hot rubidium atomic vapor cell. Choosing a double-Λ atomic energy level scheme for optimizing both spontaneous four-wave mixing nonlinear parametric interaction and electromagnetically induced transparency (EIT), we achieve a biphoton spectral brightness as high as 14 000 s−1 MHz−1. Meanwhile, we apply a spatially tailored optical pumping beam for reduction of the Raman noise and obtain a violation of the Cauchy-Schwarz inequality by a factor of 1023.
Summary form only given. Entangled photon pair is key factor for realization of quantum communication, quantum information, etc. For long distance quantum communication, it is necessary to generate narrow band biphoton for interaction with atomic based quantum memory. In recent years, generation of time-frequency entangled photon pairs based on spontaneous four-wave mixing (SFWM) process in atomic ensemble have been reported [1-3]. Very recently, S. Chu et al. achieved generation of strongly correlated subnatural-linewidth biphoton from Doppler-broaden hot atomic ensemble [4]. The group used paraffin-coated87Rb vapour cell and separated optical pumping effect for reduce noise of fluorescence from resonant coupling field. In this paper, we performed experiment for subnatural-linewidth biphoton generation from hot atomic ensembles by using a hollow optical pumping field and regular vapour cell, which are not special coated cell.
We explore a mechanism for producing time-frequency entangled photon pairs (termed a biphoton) from an ensemble of atom-like solid-state quantum emitters. Four distinct energy levels of the solid-state system render four spin-conserving optical transitions as observed in color centers. This feature opens up the possibility to generate a four-wave mixing biphoton based on an electromagnetic induced transparency (EIT) for long-coherence quantum communication as demonstrated in cold atomic systems. We propose a narrow EIT window below a lifetime-limited linewidth of a SiV− in diamond, assuming a few hundred MHz. Consequently, the EIT-induced narrowband guarantees biphoton coherence time to be at least a few tens of a nanosecond without a cavity. Assessing the criteria of solid-state parameters applicable to the existing biphoton model from cold atoms will accelerate solid-state biphoton source research. This study shows that a realization of negligible ground state dephasing of a solid-state sample will be a crucial step toward a solid-state biphoton generation for more than a 100 ns time scale with a subnatural atomic linewidth of a few MHz.
We utilized the all-copropagating scheme, which maintains the phase-match condition, in the spontaneous four-wave mixing (SFWM) process to generate biphotons from a hot atomic vapor. The linewidth and spectral brightness of our biphotons surpass those of the biphotons produced with the hot-atom SFWM in the previous works. Moreover, the generation rate of the sub-MHz biphoton source in this work can also compete with those of the sub-MHz biphoton sources of the cold-atom SFWM or cavity-assisted spontaneous parametric down conversion. Here, the biphoton linewidth is tunable for an order of magnitude. As we tuned the linewidth to 610 kHz, the generation rate per linewidth is 1,500 pairs/(s·MHz) and the maximum two-photon correlation function, g s , a s ( 2 ) , of the biphotons is 42. This g s , a s ( 2 ) violates the Cauchy-Schwarz inequality for classical light by 440 folds, and demonstrates that the biphotons have a high purity. By increasing the pump power by 16 folds, we further enhanced the generation rate per linewidth to 2.3×10 4 pairs/(s·MHz), while the maximum g s , a s ( 2 ) became 6.7. In addition, we are able to tune the linewidth down to 290±20 kHz. This is the narrowest linewidth to date among all single-mode biphoton sources of room-temperature and hot media.