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Superfluid-Mott-Insulator Transition in an Optical Lattice with Adjustable Ensemble-Averaged Filling Factors |
| Shifeng Yang1, Tianwei Zhou1, Chen Li2, Kaixiang Yang1, Yueyang Zhai3**, Xuguang Yue4, Xuzong Chen1** |
1School of Electronics Engineering and Computer Science, Peking University, Beijing 100871
2Vienna Center for Quantum Science and Technology, Atominstitut, TU-Wien, Stadionallee 2, 1020 Vienna, Austria
3Innovative Research Institute of Frontier Science and Technology, Beihang University, Beijing 100191
4Wuhan National Laboratory for Optoelectronics (WNLO), Wuhan 430074
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| Cite this article: |
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Shifeng Yang, Tianwei Zhou, Chen Li et al 2020 Chin. Phys. Lett. 37 040301 |
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Abstract We study the quantum phase transition from a superfluid to a Mott insulator of ultracold atoms in a three-dimensional optical lattice with adjustable filling factors. Based on the density-adjustable Bose–Einstein condensate we prepared, the excitation spectrum in the superfluid and the Mott insulator regime is measured with different ensemble-averaged filling factors. We show that for the superfluid phase, the center of the excitation spectrum is positively correlated with the ensemble-averaged filling factor, indicating a higher sound speed of the system. For the Mott insulator phase, the discrete feature of the excitation spectrum becomes less pronounced as the ensemble-averaged filling factor increases, implying that it is harder for the system to enter the Mott insulator regime with higher filling factors. The ability to manipulate the filling factor affords further potential in performing quantum simulation with cold atoms trapped in optical lattices.
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Received: 07 December 2019
Published: 24 March 2020
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| PACS: |
03.75.Hh
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(Static properties of condensates; thermodynamical, statistical, and structural properties)
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37.10.Jk
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(Atoms in optical lattices)
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03.65.Nk
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(Scattering theory)
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| Fund: Supported by the National Natural Science Foundation of China (Grant Nos. 61703025, 91736208, 11504328, and 11920101004), the National Program on Key Basic Research Project of China (Grant Nos. 2016YFA0301501 and 2017YFA0304204). |
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| [1] | Greiner M and Fölling S 2008 Nature 453 736 | | [2] | Bloch I, Dalibard J and Nascimbène S 2012 Nat. Phys. 8 267 | | [3] | Gross C and Bloch I 2017 Science 357 995 | | [4] | Bloch I 2005 Nat. Phys. 1 23 | | [5] | Bloch I, Dalibard J and Zwerger W 2008 Rev. Mod. Phys. 80 885 | | [6] | Jaksch D, Bruder C, Cirac J I, Gardiner C W and Zoller P 1998 Phys. Rev. Lett. 81 3108 | | [7] | Greiner M, Mandel O, Esslinger T, Hänsch T W and Bloch I 2002 Nature 415 39 | | [8] | Fisher M, Weichman P, Grinstein G and Fisher D 1989 Phys. Rev. B 40 546 | | [9] | Kashurnikov V A, Prokofév N V and Svistunov B V 2002 Phys. Rev. A 66 031601 | | [10] | Oosten D, Straten P and Stoof C 2003 Phys. Rev. A 67 033606 | | [11] | Li C, Zhou T, Zhai Y, Xiang J, Luan T, Huang Q, Yang S, Xiong W and Chen X 2017 Rev. Sci. Instrum. 88 053104 | | [12] | Zhou T, Yang K, Zhu Z, Yu X, Yang S, Xiong W, Zhou X, Chen X, Li C, Schmiedmayer J, Yue X and Zhai Y 2019 Phys. Rev. A 99 013602 | | [13] | Zhou T, Yang K, Zhai Y, Yue X, Yang S, Xiang J, Huang Q, Xiong W, Zhou X and Chen X 2018 Opt. Express 26 16726 | | [14] | Mark M J, Haller E, Lauber K, Danzl J G, Daley A J and Nägerl H C 2011 Nature 107 175301 | | [15] | Stöferle T, Moritz H, Schori C, Köhl M and Esslinger T 2004 Phys. Rev. Lett. 92 130403 | | [16] | Köhl M, Moritz H, Stöferle T, Schori C, Esslinger T 2005 J. Low Temp. Phys. 138 635 | | [17] | Oosten D, Straten P and Stoof C 2001 Phys. Rev. A 63 053601 |
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