量子电子学报, 2016, 33 (4): 456, 网络出版: 2016-10-24  

相变温度以上超冷玻色气体的一阶空间相干性

First-order spatial coherence of ultracold Bose gas above phase transition temperature
孙超 1,2,3,*王兵 1,2,3朱强 1,2,3熊德智 1,2
作者单位
1 中国科学院武汉物理与数学研究所,波谱与原子分子物理国家重点实验室, 湖北 武汉 430071
2 中国科学院原子频标重点实验室, 湖北 武汉 430071
3 中国科学院大学, 北京 100049
摘要
利用一维光学驻波场产生的相位光栅对静磁阱中相变温度以上超冷原子气体的一阶相干性质进行研究。 理论计算了热原子的干涉图样,实验获得了相变温度以上超冷原子气体的干涉图样。通过比较理论和实验原 子气体干涉图样的对比度发现:当超冷原子气体温度非常接近相变温度时,原子气体的相干性明显好于热 原子的相干性;随着温度的升高,原子气体的相干性逐渐减弱,最终与热原子的相干性完全相同。
Abstract
The first-order spatial coherence of ultracold Bose gas above the phase transition temperature in static-magnetic trap is investigated by using phase grating produced by one dimensional optical standing wave field. The interference patterns of thermal atoms are calculated in theory, and the interference patterns of ultracold atomic gas above the phase transition temperature are also obtained by experiments. By comparing the contrast of interference patterns of atomic gas in theory and experiment, it’s found that when the temperature of ultracold atomic gas is very close to the phase transition temperature, coherence of the atomic gas is better than that of thermal atom. With increasing of temperature, the coherence of atomic gas decreases gradually, and it is the same as that of thermal atom finally.
参考文献

[1] Anderson M H, Ensher J R, Matthews M R, et al. Observation of Bose-Einstein condensation in a dilute atomic vapor[J]. Science, 1995, 269(5221): 198-201.

[2] Davis K B, Mewes M O, Andrews M R, et al. Bose-Einstein condensation in a gas of sodium atoms[J]. Phys. Rev. Lett., 1995, 75(22): 3969-3973.

[3] Bradley C C, Sackett C A, Tollett J J, et al. Evidence of Bose-Einstein condensation in an atomic gas with attractive interactions[J]. Phys. Rev. Lett., 1995, 75(9): 1687-1690.

[4] Andrews M R, Townsend C G, Miesner H J, et al. Observation of interference between two Bose condensates[J]. Science, 1997, 275(5300): 637-641.

[5] Hagley E W, Deng L, Kozuma M, et al. Measurement of the coherence of a Bose-Einstein condensate[J]. Phys. Rev. Lett., 1999, 83(16): 3112-3115.

[6] Liu Xiayin, Su Yanping, Xu Zhijun. Detection of quantum vortex by interference of Bose-condensed gas in a double-well trap[J]. Chinese Journal of Quantum Electronics (量子电子学报), 2011, 28(3): 313-317 (in Chinese).

[7] Barnert S M, Franke-Arnold S, Arnold A S, et al. Coherence length for a trapped Bose gas[J]. J. Phys. B: At. Mol. Opt. Phys., 2000, 33(19): 4177-4191.

[8] Donner T, Ritter S, Bourdel T, et al. Critical behavior of a trapped interacting Bose gas[J]. Science, 2007, 315(5818): 1556-1558.

[9] Xiong Wei, Zhou Xiaoji, Yue Xuguang, et al. Critical correlations in an ultra-cold Bose gas revealed by means of a temporal Talbot-Lau interferometer[J]. Laser Phys. Lett., 2013, 10(12): 125502.

[10] Bezett A, Toth E, Blakie P B. Two-point correlations of a trapped interacting Bose gas at finite temperature[J]. Phys. Rev. A, 2008, 77(2): 023602.

[11] Naraschewski M, Glauber R J. Spatial coherence and density correlations of trapped Bose gases[J]. Phys. Rev. A, 1999, 59(6): 4595-4607.

[12] Bloch I, Hansch T W, Esslinger T. Measurement of the spatial coherence of a trapped Bose gas at the phase transition[J]. Nature, 2000, 403(6766): 166-170.

[13] Anderson B P, Kasevich M A. Macroscopic quantum interference from atomic tunnel arrays[J]. Science, 1998, 282(5394): 1686-1689.

[14] Orzel C, Tuchman A K, Fenselau M L, et al. Squeezed states in a Bose-Einstein condensate[J]. Science, 2001, 291(5512): 2386-2389.

[15] Wang Bing, Zhu Qiang, Zhou Hailong, et al. Measurement of phase fluctuations of Bose-Einstein condensates in an optical lattice[J]. Phys. Rev. A, 2012, 8(5): 053609.

[16] Zhou Hailong, Zhu Qiang, Wang Bing, et al. Measurement of phase fluctuations of Bose-Einstein condensates in one dimensional optical lattice[J]. Chinese Journal of Quantum Electronics (量子电子学报), 2014, 31(1): 56-60 (in Chinese).

[17] Zambelli F, Pitaevskii L, Stamper-Kurn D M, et al. Dynamic structure factor and momentum distribution of a trapped Bose gas[J]. Phys. Rev. A, 2000, 61(6): 063608.

[18] Sapiro R E, Zhang R, Raithel G. Reversible loss of superfluidity of a Bose-Einstein condensate in a 1D optical lattice[J]. New J. Phys., 2009, 11(1): 013013.

[19] Gould P L, Ruff G A, Pritchard D E. Diffraction of atoms by light: The near-resonant Kapitza-Dirac effect[J]. Phys. Rev. Lett., 1986, 5(8): 827-830.

[20] Bezett A, Blakie P B. Critical properties of a trapped interacting Bose gas[J]. Phys. Rev. A, 2009, 79(3): 033611.

[21] Pethick C J, Smith H. Bose-Einstein Condensation in Dilute Gases[M]. Cambridge: Cambridge University Press, 2008: 21-23.

[22] Lu Baolong, Tan Xinzhou, Wang Bing, et al. Phase transition to Bose-Einstein condensation for a bosonic gas confined in a combined trap[J]. Phys. Rev. A, 2010, 82(5): 053629.

孙超, 王兵, 朱强, 熊德智. 相变温度以上超冷玻色气体的一阶空间相干性[J]. 量子电子学报, 2016, 33(4): 456. SUN Chao, WANG Bing, ZHU Qiang, XIONG Dezhi. First-order spatial coherence of ultracold Bose gas above phase transition temperature[J]. Chinese Journal of Quantum Electronics, 2016, 33(4): 456.

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