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

中国物理B：英文版

Experimental study of the dependences of retrieval efficiencies on time delay between magneto-optical-trap being turned off and optical storage

陈力荣, 徐忠孝, 李萍, 温亚飞, 曾炜卿, 武跃龙, 田龙, 李淑静, 王海

Published Jan 1, 2016• 0 citations
OpenAlex

Abstract

We report an experimental study of electromagnetically induced transparency(EIT)-based light storage in a cloud of cold atoms loaded into a magneto-optical-trap(MOT). After the MOT is turned off, the retrieval efficiencies of rightand left-circularly polarized signal light fields each as a function of storage time are measured for different time delays between MOT off and the storage event, respectively. The results show that in the delay ranging from 0.015 ms to 3.5 ms,the retrieval efficiency for a zero-storage time(0.2 μs) and the storage lifetime can exceed 15% and 1.4 ms, respectively.The measured results will provide important help for optimizing the storage of the polarized entanglement photons in cold atomic ensembles.

Related papers

Cavity-enhanced and long-lived optical memories for two orthogonal polarizations in cold atoms

Yafei Wen, Pai Zhou, Zhongxiao Xu +5 more

The storage and retrieval efficiency (SRE) and lifetime of optical quantum memories are two key performance indicators for scaling up quantum information processing. Here, we experimentally demonstrate a cavity-enhanced long-lived optical memory for two polarizations in a cold atomic ensemble. Using electromagnetically induced-transparency (EIT) dynamics, we demonstrate the storages of left-circularly and right-circularly polarized signal light pulses in the atoms, respectively. By making the signal and control beams collinearly pass through the atoms and storing the two polarizations of the signal light as two magnetic-field-insensitive spin waves, we achieve a long-lived (3.5 ms) memory. By placing a low-finesse optical ring cavity around the cold atoms, the coupling between the signal light and the atoms is enhanced, which leads to an increase in SRE. The presented cavity-enhanced storage shows that the SRE is ∼30%, corresponding to an intrinsic SRE of ∼45%.

Optics Express•Dec 19, 2019•6 citations

Highly-efficient optical storage of two orthogonal polarization modes in a cold atom ensemble

Yafei Wen, Shengzhi Wang, Xu Zhong-Xiao +2 more

Optical quantum memory plays an important role in scaling-up linear optical quantum computations and longdistance quantum communication. For effectively realizing such tasks, a long-lived and highly-efficient quantum memory is needed. The dynamic electromagnetically-induced-transparency (EIT) process can be used for completing an absorptive storage scheme in an atomic ensemble. In such a process, the quantum states of coming single photons can be coherently transformed into spin waves associated with coherences between atomic ground levels via switching off controlling light beam. For storing a single-mode optical signal, a pair of ground levels is involved. While for storing an optical polarization qubit, i.e., two orthogonal polarization modes, the coherence between two pairs of ground levels will be involved. Also, to obtain a high efficiency in the EIT optical storage, the optical-depth of the cold ensemble should be high. For prolonging the coherent time of the spin waves stored in atomic ensemble, decoherence between spin waves due to atomic motion and non-uniform Zeeman shift of ground levels should be effectively suppressed. Recently, a long-lived and highly-efficient optical quantum memory for single-mode storage in a high-optical-depth cold atom ensemble has been experimentally demonstrated via the gradient echo memory scheme (2016 Optical 3 100). While, for the optical polarization qubit storage, a long lifetime (in ms) and high-fidelity EIT storage experiment has been achieved by our group, but the storage efficiency in the experiment is very low (8%) due to lower optical depth of the cold ensemble (2013 Phys. Rev. Lett. 111 240503). The storage efficiency in long-lived storage of two orthogonal polarization modes still needs further improving. Here in this paper we demonstrate an experiment of long-lived and highly-efficient storage of two optical orthogonal polarization modes in a high optical-depth cold atomic ensemble via dynamic EIT process. For achieving a long lifetime in the storage experiment, we follow the two steps, which are used in our previous work (2013 Phys. Rev. Lett. 111 240503). 1) We make the signal and writing-reading light beams collinearly pass through the cold-atom cloud along the z direction to suppress the decoherence between the spin waves due to atomic motion. 2) We apply a moderate magnetic field (13.5 G) to the cold-atom ensemble to lift Zeeman degeneracy. So, the magnetic-field-sensitive transitions are removed from EIT system and the two optical orthogonal polarization modes are stored as two magnetic-field-insensitive spin waves. In contrast to our previous experiment, we finish the storage in the high optical-depth cold atomic ensemble. To obtain such a high optical-depth cold atomic ensemble, we expand the diameters of the trapping laser beams and use a pair of rectangular magnetic coils in a magnetic optical trap (MOT) to prepare a cigar-shaped cold atomic ensemble. The MOT magnetic field is further compressed, and then the optical-depth of the cold atomic ensemble increases up to ~11 in the present experiment, which allows us to achieve a storage efficiency of 30%, which exceeds the previous value (8%). At an MOT repetition rate of 10 Hz, the measured zero-delay storage efficiencies for the two orthogonal polarization modes are symmetric, which go up to ~30%. The 1/e-folding lifetimes of the two orthogonal polarization modes rise up to 3 ms. We also measure the dependence of the zero-delay retrieval efficiency on the MOT repetition rate F and find that the storage efficiency is still more than 20% when the repetition rate F is 50 Hz. The present results will allow one to achieve a long lifetime and highly-efficient quantum memory for photonic polarization qubit and then find applications in scaling-up linear-optical quantum computations and long-distance quantum communication.

Acta Physica Sinica•Jan 1, 2018•0 citations

Experimental study of the effects of two-photon detuning on slow light and light memory

Yan Yan, 李淑静 LI Shu-jing, Tian Long +1 more

Electromagnetically induced transparency (EIT) effect is an effective means to store light field into the atom ensemble. The extra noise introduced in the stored procedure can be suppressed greatly under the condition of large one-photon detuning and proper two-photon detuning. In this paper, we experimentally investigate the slow light and light storage in 87Rb vapor by using EIT effect, and study the effects of the two-photon detuning on light pulse delay and light memory at 650 MHz one-photon red detuning. In order to avoid some unwanted effects under the high optical depth condition, such as four-wave mixing, etc., the temperature of the atomic cell is controlled at 65 degrees Celsius. The experimental results show that the delay and the retrieval signals are significant in a two-photon detuning range from 0 to 0.5 MHz. The pulse delay decreases with the increase of two-photon detuning. The delay is 0.36 ups at two-photon resonance, and it is 0.07 ups at 1 MHz two-photon detuning. We simulate the delayed light pulse by using a three-level -type EIT model. The shapes of the measured slow light are in agreement with the theoretical results. The retrieval signals are observed at different two-photon detunings. The shapes of the retrieval pulses change with the two-photon detuning. The shape variations of the retrieval pulses cannot be explained by the three-level EIT theoretical model. By considering the atomic Zeeman sublevels interacting with the left-circular and right-circular polarized components of probe and coupling fields, multiple -type EIT systems will be formed. The interference between the retrieval signals from multiple EIT subsystems causes the shape distortions of retrieval pulses. The retrieval efficiency is measured as a function of two-photon detuning. The retrieval efficiency oscillates, and multiple peaks appear with the increase of two-photon detuning. The first peak appears at two-photon resonance, and the second peak appears at 0.48 MHz two-photon detuning. Finally, we measure the retrieval efficiency as a function of the coupling power at 0.48 MHz two-photon detuning. The optimal retrieval efficiency reaches 25% when the coupling power is 100 mW. These results provide experimental reference for the quantum memory of continuous variables in the hot atom ensemble.

Acta Physica Sinica•Jan 1, 2016•3 citations

Optimal storage and retrieval of single-photon waveforms

Shuyu Zhou, Shanchao Zhang, Chang Liu +5 more

We report an experimental demonstration of optimal storage and retrieval of heralded single-photon wave packets using electromagnetically induced transparency (EIT) in cold atoms at a high optical depth. We obtain an optimal storage efficiency of (49 ± 3)% for single-photon waveforms with a temporal likeness of 96%. Our result brings the EIT quantum light-matter interface closer to practical quantum information applications.

arXiv:1207.2670•Optics Express•Oct 8, 2012•75 citations

Experimental study of the dependences of retrieval efficiencies on time delay between magneto-optical-trap being turned off and optical storage

Lirong Chen, Zhongxiao Xu, Ping Li +6 more

Experimental study of the dependences of retrieval efficiencies on time delay between magneto-optical-trap being turned off and optical storage*, Chen, Li-Rong, Xu, Zhong-Xiao, Li, Ping, Wen, Ya-Fei, Zeng, Wei-Qing, Wu, Yue-Long, Tian, Long, Li, Shu-Jing, Wang, Hai

Chinese Physics B•Feb 1, 2016•2 citations

Theoretical design for generation of slow light in a two-dimensional magneto optical trap using electromagnetically induced transparency

Sumit Bhushan, Raghavan K. Easwaran

In this paper, we propose a novel technique for slow light experiments using electromagnetically induced transparency using a two-dimensional magneto optical trap (2D-MOT). A compact 2D-MOT design efficient for quantum memory applications with adjustable optical depth (OD) is proposed. We estimated the OD for our 2D-MOT setup and found that light group velocities as low as 1.4 m/s can be attained. Our design for 2D-MOT allows precise control and optimization of the OD such that high storage efficiencies could also be achieved. With our design, it is possible to obtain a delay bandwidth product of 163, which is very high in comparison to previously obtained values.

Applied Optics•Apr 25, 2017•13 citations
We report an experimental study of electromagnetically induced transparency(EIT)-based light storage in a cloud of cold atoms loaded into a magneto-optical-trap(MOT). After the MOT is turned off, the retrieval efficiencies of rightand left-circularly polarized signal light fields each as a function of storage time are measured for different time delays between MOT off and the storage event, respectively. The results show that in the delay ranging from 0.015 ms to 3.5 ms,the retrieval efficiency for a zero-storage time(0.2 μs) and the storage lifetime can exceed 15% and 1.4 ms, respectively.The measured results will provide important help for optimizing the storage of the polarized entanglement photons in cold atomic ensembles.
The storage and retrieval efficiency (SRE) and lifetime of optical quantum memories are two key performance indicators for scaling up quantum information processing. Here, we experimentally demonstrate a cavity-enhanced long-lived optical memory for two polarizations in a cold atomic ensemble. Using electromagnetically induced-transparency (EIT) dynamics, we demonstrate the storages of left-circularly and right-circularly polarized signal light pulses in the atoms, respectively. By making the signal and control beams collinearly pass through the atoms and storing the two polarizations of the signal light as two magnetic-field-insensitive spin waves, we achieve a long-lived (3.5 ms) memory. By placing a low-finesse optical ring cavity around the cold atoms, the coupling between the signal light and the atoms is enhanced, which leads to an increase in SRE. The presented cavity-enhanced storage shows that the SRE is ∼30%, corresponding to an intrinsic SRE of ∼45%.
Optical quantum memory plays an important role in scaling-up linear optical quantum computations and longdistance quantum communication. For effectively realizing such tasks, a long-lived and highly-efficient quantum memory is needed. The dynamic electromagnetically-induced-transparency (EIT) process can be used for completing an absorptive storage scheme in an atomic ensemble. In such a process, the quantum states of coming single photons can be coherently transformed into spin waves associated with coherences between atomic ground levels via switching off controlling light beam. For storing a single-mode optical signal, a pair of ground levels is involved. While for storing an optical polarization qubit, i.e., two orthogonal polarization modes, the coherence between two pairs of ground levels will be involved. Also, to obtain a high efficiency in the EIT optical storage, the optical-depth of the cold ensemble should be high. For prolonging the coherent time of the spin waves stored in atomic ensemble, decoherence between spin waves due to atomic motion and non-uniform Zeeman shift of ground levels should be effectively suppressed. Recently, a long-lived and highly-efficient optical quantum memory for single-mode storage in a high-optical-depth cold atom ensemble has been experimentally demonstrated via the gradient echo memory scheme (2016 Optical 3 100). While, for the optical polarization qubit storage, a long lifetime (in ms) and high-fidelity EIT storage experiment has been achieved by our group, but the storage efficiency in the experiment is very low (8%) due to lower optical depth of the cold ensemble (2013 Phys. Rev. Lett. 111 240503). The storage efficiency in long-lived storage of two orthogonal polarization modes still needs further improving. Here in this paper we demonstrate an experiment of long-lived and highly-efficient storage of two optical orthogonal polarization modes in a high optical-depth cold atomic ensemble via dynamic EIT process. For achieving a long lifetime in the storage experiment, we follow the two steps, which are used in our previous work (2013 Phys. Rev. Lett. 111 240503). 1) We make the signal and writing-reading light beams collinearly pass through the cold-atom cloud along the z direction to suppress the decoherence between the spin waves due to atomic motion. 2) We apply a moderate magnetic field (13.5 G) to the cold-atom ensemble to lift Zeeman degeneracy. So, the magnetic-field-sensitive transitions are removed from EIT system and the two optical orthogonal polarization modes are stored as two magnetic-field-insensitive spin waves. In contrast to our previous experiment, we finish the storage in the high optical-depth cold atomic ensemble. To obtain such a high optical-depth cold atomic ensemble, we expand the diameters of the trapping laser beams and use a pair of rectangular magnetic coils in a magnetic optical trap (MOT) to prepare a cigar-shaped cold atomic ensemble. The MOT magnetic field is further compressed, and then the optical-depth of the cold atomic ensemble increases up to ~11 in the present experiment, which allows us to achieve a storage efficiency of 30%, which exceeds the previous value (8%). At an MOT repetition rate of 10 Hz, the measured zero-delay storage efficiencies for the two orthogonal polarization modes are symmetric, which go up to ~30%. The 1/e-folding lifetimes of the two orthogonal polarization modes rise up to 3 ms. We also measure the dependence of the zero-delay retrieval efficiency on the MOT repetition rate F and find that the storage efficiency is still more than 20% when the repetition rate F is 50 Hz. The present results will allow one to achieve a long lifetime and highly-efficient quantum memory for photonic polarization qubit and then find applications in scaling-up linear-optical quantum computations and long-distance quantum communication.
Electromagnetically induced transparency (EIT) effect is an effective means to store light field into the atom ensemble. The extra noise introduced in the stored procedure can be suppressed greatly under the condition of large one-photon detuning and proper two-photon detuning. In this paper, we experimentally investigate the slow light and light storage in 87Rb vapor by using EIT effect, and study the effects of the two-photon detuning on light pulse delay and light memory at 650 MHz one-photon red detuning. In order to avoid some unwanted effects under the high optical depth condition, such as four-wave mixing, etc., the temperature of the atomic cell is controlled at 65 degrees Celsius. The experimental results show that the delay and the retrieval signals are significant in a two-photon detuning range from 0 to 0.5 MHz. The pulse delay decreases with the increase of two-photon detuning. The delay is 0.36 ups at two-photon resonance, and it is 0.07 ups at 1 MHz two-photon detuning. We simulate the delayed light pulse by using a three-level -type EIT model. The shapes of the measured slow light are in agreement with the theoretical results. The retrieval signals are observed at different two-photon detunings. The shapes of the retrieval pulses change with the two-photon detuning. The shape variations of the retrieval pulses cannot be explained by the three-level EIT theoretical model. By considering the atomic Zeeman sublevels interacting with the left-circular and right-circular polarized components of probe and coupling fields, multiple -type EIT systems will be formed. The interference between the retrieval signals from multiple EIT subsystems causes the shape distortions of retrieval pulses. The retrieval efficiency is measured as a function of two-photon detuning. The retrieval efficiency oscillates, and multiple peaks appear with the increase of two-photon detuning. The first peak appears at two-photon resonance, and the second peak appears at 0.48 MHz two-photon detuning. Finally, we measure the retrieval efficiency as a function of the coupling power at 0.48 MHz two-photon detuning. The optimal retrieval efficiency reaches 25% when the coupling power is 100 mW. These results provide experimental reference for the quantum memory of continuous variables in the hot atom ensemble.
In this paper, we propose a novel technique for slow light experiments using electromagnetically induced transparency using a two-dimensional magneto optical trap (2D-MOT). A compact 2D-MOT design efficient for quantum memory applications with adjustable optical depth (OD) is proposed. We estimated the OD for our 2D-MOT setup and found that light group velocities as low as 1.4 m/s can be attained. Our design for 2D-MOT allows precise control and optimization of the OD such that high storage efficiencies could also be achieved. With our design, it is possible to obtain a delay bandwidth product of 163, which is very high in comparison to previously obtained values.