Characterization of cold atoms based on photoionization momentum spectra

doi:10.1088/1674-1056/add00d

中国物理B ›› 2025, Vol. 34 ›› Issue (7): 73202-073202.doi: 10.1088/1674-1056/add00d

所属专题： SPECIAL TOPIC — Ultrafast physics in atomic, molecular and optical systems

Characterization of cold atoms based on photoionization momentum spectra

Zhixian Wu(吴志贤)¹, Shushu Ruan(阮舒舒)², Zhenjie Shen(沈镇捷)^1,†, Jie Liu(刘杰)², Xinglong Yu(余兴龙)², Lifeng Chen(陈利丰)¹, Bing Zhu(朱兵)³, Xincheng Wang(王新成)¹, and Yuhai Jiang(江玉海)^1,2,4,‡

1 Center for Transformative Science and School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China;
2 Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China;
3 HSBC Laboratory, Guangzhou 510510, China;
4 School of Physics, Henan Normal University, Xinxiang 453007, China

收稿日期:2025-03-13 修回日期:2025-04-18 接受日期:2025-04-24 出版日期:2025-06-18 发布日期:2025-06-18
通讯作者: Zhenjie Shen, Yuhai Jiang E-mail:shenzhj2@shanghaitech.edu.cn;jiangyh3@shanghaitech.edu.cn
基金资助:
Project supported by the Natural Science Foundation of Henan (Grant No. 252300421304), the National Natural Science Foundation of China (Grant Nos. 12204498, 12474259, and 12334011), and the National Key Research and Development Program of China (Grant No. 2022YFA1604302).

Characterization of cold atoms based on photoionization momentum spectra

1 Center for Transformative Science and School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China;
2 Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China;
3 HSBC Laboratory, Guangzhou 510510, China;
4 School of Physics, Henan Normal University, Xinxiang 453007, China

Received:2025-03-13 Revised:2025-04-18 Accepted:2025-04-24 Online:2025-06-18 Published:2025-06-18
Contact: Zhenjie Shen, Yuhai Jiang E-mail:shenzhj2@shanghaitech.edu.cn;jiangyh3@shanghaitech.edu.cn
Supported by:
Project supported by the Natural Science Foundation of Henan (Grant No. 252300421304), the National Natural Science Foundation of China (Grant Nos. 12204498, 12474259, and 12334011), and the National Key Research and Development Program of China (Grant No. 2022YFA1604302).

摘要/Abstract

摘要： We propose a method to characterize the features of a cold strontium cloud in a magneto-optical trap (MOT) through the photoionization of cold Sr atoms in a custom-designed reaction microscope. Sr atoms in the dark state of $\mathrm{5s5p \, ^3P_2}$ populated via the cascade transition $\mathrm{5s5p \, ^1P_1 \rightarrow 5s4d \, ^1D_2 \rightarrow 5s5p \, ^3P_2}$ accumulate a significant fraction, giving a long lifetime of 520 s. These atoms in the dark state are subsequently trapped by the gradient magnetic field of the MOT. By scanning the Sr$^+$ momentum distributions ionized with an 800 nm infrared femtosecond laser, we are able to outline the size of $\sim0.55$ mm in radius and the temperature of $\sim0.40$ mK for the dark-state atoms, which is significantly cooler than the MOT temperature of 3.3 mK trapped in the 461 nm. The size of MOT exhibits an oblate spheroidal distribution with a radius of approximately 0.35 mm and 0.55 mm, extracted with momenta of photoion and absorption imaging, respectively. The results using the photoion momenta are consistent with the expected results from absorption imaging, which confirms the method's reliability. The advantage of this method is the ability to simultaneously characterize the distribution information of atoms in different initial states within the cold atomic cloud.

关键词: multiphoton ionization, photoelectron momentum, magneto-optical trap (MOT)

Abstract: We propose a method to characterize the features of a cold strontium cloud in a magneto-optical trap (MOT) through the photoionization of cold Sr atoms in a custom-designed reaction microscope. Sr atoms in the dark state of $\mathrm{5s5p \, ^3P_2}$ populated via the cascade transition $\mathrm{5s5p \, ^1P_1 \rightarrow 5s4d \, ^1D_2 \rightarrow 5s5p \, ^3P_2}$ accumulate a significant fraction, giving a long lifetime of 520 s. These atoms in the dark state are subsequently trapped by the gradient magnetic field of the MOT. By scanning the Sr$^+$ momentum distributions ionized with an 800 nm infrared femtosecond laser, we are able to outline the size of $\sim0.55$ mm in radius and the temperature of $\sim0.40$ mK for the dark-state atoms, which is significantly cooler than the MOT temperature of 3.3 mK trapped in the 461 nm. The size of MOT exhibits an oblate spheroidal distribution with a radius of approximately 0.35 mm and 0.55 mm, extracted with momenta of photoion and absorption imaging, respectively. The results using the photoion momenta are consistent with the expected results from absorption imaging, which confirms the method's reliability. The advantage of this method is the ability to simultaneously characterize the distribution information of atoms in different initial states within the cold atomic cloud.

Key words: multiphoton ionization, photoelectron momentum, magneto-optical trap (MOT)

中图分类号: (Multiphoton ionization and excitation to highly excited states)

32.80.Rm

37.10.De (Atom cooling methods)

Zhixian Wu(吴志贤), Shushu Ruan(阮舒舒), Zhenjie Shen(沈镇捷), Jie Liu(刘杰), Xinglong Yu(余兴龙), Lifeng Chen(陈利丰), Bing Zhu(朱兵), Xincheng Wang(王新成), and Yuhai Jiang(江玉海). Characterization of cold atoms based on photoionization momentum spectra[J]. 中国物理B, 2025, 34(7): 73202-073202.

参考文献

[1] Raab E L, Prentiss M, Cable A, Chu S and Pritchard D E 1987 Phys. Rev. Lett. 59 2631
[2] Tan Z, Lu B, Han C and Lee C 2024 Chin. Phys. B 33 093701
[3] Gross C and Bloch I 2017 Science 357 995
[4] Bloch I, Dalibard J and Zwerger W 2008 Rev. Mod. Phys. 80 885
[5] Bloch I, Dalibard J and Nascimbène S 2012 Nat. Phys. 8 267
[6] Bothwell T, Kedar D, Oelker E, Robinson J M, Bromley S L, Tew W L, Ye J and Kennedy C J 2019 Metrologia 56 065004
[7] Ludlow A D, BoydMM, Ye J, Peik E and Schmidt P O 2014 Rev. Mod. Phys. 87 637
[8] Schioppo M, Brown R C, McGrew W F, Hinkley N, Fasano R J, Beloy K, Yoon T H, Milani G, Nicolodi D, Sherman J A, Phillips N B, Oates C W and Ludlow A D 2017 Nat. Photon. 11 48
[9] Zheng X, Dolde J, Lochab V, Merriman B N, Li H and Kolkowitz S 2022 Nature 602 425
[10] Li R, Yuan J,Wang X, Hou X, Zhang S, Zhu Z, Ma Y, Gao Q,Wang Z, Yan T, Qin C, Li S, Zhang Y, Weidemüller M and Jiang Y 2019 JINST 14 02022
[11] Yuan J, Ma Y, Li R, Ma H, Zhang Y, Ye D, Shen Z, Yan T, Wang X, Weidemüller M and Jiang Y 2020 Chin. Phys. Lett. 37 053201
[12] Yuan J, Liu S,Wang X, Shen Z, Ma Y, Ma H, Meng Q, Yan T M, Zhang Y, Dorn A, Weidemüller M, Ye D and Jiang Y 2020 Phys. Rev. A 102 043112
[13] Ma Y, Li R, Yuan J, Meng Q, Ma H, Ruan S, Zhang Y, Yan T, Shen Z, Wang X and Jiang Y 2020 Chinese Journal of Lasers 47 0601011 (in Chinese)
[14] Ma H, Wang X, Zhang L, Zou Z, Yuan J, Ma Y, Lv R, Shen Z, Yan T, Weidemüller M, Ye D and Jiang Y 2023 Phys. Rev. A 107 033114
[15] Ruan S, Yu X, Shen Z, Wang X, Liu J, Wu Z, Tan C, Chen P, Yan T M, Ren X, Weidemüller M, Zhu B and Jiang Y 2024 Phys. Rev. A 109 023118
[16] Ruan S, Han Y, Shen Z, Yu X, Fang Y K, Wang X, Chen A, Liu J, Wu Z, Ueda K, Weidemüller M, Zhu B, Peng L Y and Jiang Y 2024 Phys. Rev. A 110 033114
[17] Ma H, Zhang L, Wang X, Zou Z, Lv R, Shen Z, Chen A, Weidemüller M, Ueda K, Ye D and Jiang Y 2025 Phys. Rev. Lett. 134 123204
[18] Anderson M, Ensher J, Matthews M, Wieman C and Cornell E 1995 Science 269 198
[19] Cornell E A and Wieman C E 2002 Rev. Mod. Phys. 74 875
[20] Killian T C, Kulin S, Bergeson S D, Orozco L A, Orzel C and Rolston S L 1999 Phy. Rev. Lett. 83 4776
[21] Killian T C, Chen Y C, Gupta P, Laha S, Martinez Y N, Mickelson P G, Nagel S B, Saenz A D and Simien C E 2005 J. Phys. B: Atom. Mol. Opt. Phys. 38 S351
[22] Bergeson S D, Baalrud S D, Ellison C L, Grant E, Graziani F R, Killian T C, Murillo M S, Roberts J L and Stanton L G 2019 Phys. Plasmas 26 100501
[23] Qiao C, Tan C, Siegl J, Hu F, Niu Z, Jiang Y, Weidemüller M and Zhu B 2021 Phys. Rev. A 103 063313
[24] Tan C, Hu F, Niu Z, Jiang Y, Weidemüller M and Zhu B 2022 Chin. Phys. Lett. 39 093202
[25] Hu F, Tan C, Jiang Y, Weidemüller M and Zhu B 2022 Chin. Phys. B 31 016702
[26] Chu S, Hollberg L, Bjorkholm J E, Cable A and Ashkin A 1985 Phys. Rev. Lett. 55 48
[27] Lett P D, Watts R N, Westbrook C I, Phillips W D, Gould P L and Metcalf H J 1988 Phys. Rev. Lett. 61 169
[28] Xu X, Loftus T H, Hall J L, Gallagher A and Ye J 2003 J. Opt. Soc. Am. B 20 968
[29] Yasuda M and Katori H 2004 Phys. Rev. Lett. 92 153004
[30] Dimitriou A, Loriot V, Marciniak A, Barillot T, Danakas S, Lépine F, Bordas C and Cohen S 2022 Phys. Rev. A 105 053106
[31] Fabre F, Petite G, Agostini P and Clement M 1982 J. Phys. B: Atom. Mol. Opt. Phys. 15 1353
[32] Petrich W, Anderson M H, Ensher J R and Cornell E A 1994 J. Opt. Soc. Am. B 11 1332
[33] Hu F, Nosske I, Couturier L, Tan C, Qiao C, Chen P, Jiang Y H, Zhu B and Weidemüller M 2019 Phys. Rev. A 99 033422
[34] Kokkelmans S J J M F, Boesten H M J M and Verhaar B J 1997 Phys. Rev. A 55 R1589
[35] Nagel S B, Simien C E, Laha S, Gupta P, Ashoka V S and Killian T C 2003 Phys. Rev. A 67 011401

Characterization of cold atoms based on photoionization momentum spectra

Characterization of cold atoms based on photoionization momentum spectra

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