Xu Xu

Publications (7)5.46 Total impact

• Source

  Available from: Xuzong Chen

  Article: Cooperative scattering measurement of coherence in a spatially modulated Bose gas

  Bo Lu, Thibault Vogt, Xinxing Liu, Xu Xu, Xiaoji Zhou, Xuzong Chen
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  ABSTRACT: Correlations of a Bose gas released from an optical lattice are measured using superradiant scattering. Conditions are chosen so that after initial incident light pumping at the Bragg angle for diffraction, due to matter wave amplification and mode competition, superradiant scattering into the Bragg diffracted mode is preponderant. A temporal analysis of the superradiant scattering gain reveals periodical oscillations and damping due to the initial lack of coherence between lattice sites. Such damping is used for characterizing first order spatial correlations in our system with a precision of one lattice period.
  05/2011;
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  Available from: Xuzong Chen

  Article: Mode competition in superradiant scattering of matter waves

  Thibault Vogt, Bo Lu, Xinxing Liu, Xu Xu, Xiaoji Zhou, Xuzong Chen
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  ABSTRACT: Superradiant Rayleigh scattering in a Bose gas released from an optical lattice is analyzed with incident light pumping at the Bragg angle for resonant light diffraction. We show competition between superradiance scattering into the Bragg mode and into end-fire modes clearly leads to suppression of the latter at even relatively low lattice depths. A quantum light-matter interaction model is proposed for qualitatively explaining this result.
  03/2011;
• Article: Detecting quantum coherence of Bose gases in optical lattices by scattering light intensity in cavity.

  Xiaoji Zhou, Xu Xu, Lan Yin, W M Liu, Xuzong Chen
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  ABSTRACT: We propose a new method of detecting quantum coherence of a Bose gas trapped in a one-dimensional optical lattice by measuring the light intensity from Raman scattering in cavity. After pump and displacement process, the intensity or amplitude of scattering light is different for different quantum states of a Bose gas, such as superfluid and Mott-Insulator states. This method can also be useful to detect quantum states of atoms with two components in an optical lattice.
  Optics Express 07/2010; 18(15):15664-71. · 3.59 Impact Factor
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  Available from: Xuzong Chen

  Article: Spectroscopy of Superradiant scattering from an array of Bose-Einstein Condensates

  Xu Xu, Xiaoji Zhou, Xuzong Chen
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  ABSTRACT: We theoretically study the superradiant gain and the direction of this coherent radiant for an array of Bose-Einstein condensates in an optical lattice. We find that the density grating is formed to amplify the scattering light within the phase match condition. The scattering spectroscopy in the momentum space can provide a method for measuring the overlap of wavefunction between the neighboring sites, which is related to their inner-site and inter-site coherence.
  10/2008;
• Article: Resonant Raman super-radiance in a Bose–Einstein condensate with two internal states

  Xu Xu, Xiaoji Zhou, Xuzong Chen
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  ABSTRACT: A general semi-classical theory for the super-radiance in a Bose–Einstein condensate with two internal states is given. In the case dominated by Rayleigh-forward and Raman-backward processes, a large number of backward recoiling atoms can be generated by one frequency laser. Moreover, this scheme could be used to measure the scattered light spectrum, via the control of the energy difference between two internal states, and to confirm the process of forward and resonant backward recoil.
  Journal of Physics B Atomic Molecular and Optical Physics 08/2008; 41(16):165302. · 1.88 Impact Factor
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  Available from: Xuzong Chen

  Article: The inherent fluctuations of the pulsed atom laser produced in the F=2 manifold

  Lin Xia, Fan Yang, Xu Xu, Xiaoji Zhou, Xuzong Chen
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  ABSTRACT: The obvious fluctuations of the pulsed atom laser beams from the F=2 manifold are experimentally observed under the condition that the back-coupling noise mechanics can be neglected. The one-dimensional Gross-Pitaevskii model for atom lasers is used, and the simulation fits the experiments. The fluctuations do not decrease by decreasing the coupling strength, which is different from continuously outcoupled atom laser. It shows that the loss of atoms in the condensate leads to fluctuations of the atom laser, which is inherent in all state changing outcoupling, such as rf and Raman. The interference of outcoupled matter wave is found to be another new noise mechanics leading to severe fluctuations.
  03/2008;
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  Available from: Xuzong Chen

  Article: Manipulation of the quantum state by Majorana transition in spinor Bose-Einstein condensates

  Lin Xia, Xu Xu, Fan Yang, Wei Xiong, Juntao Li, Qianli Ma, Xiaoji Zhou, Hong Guo, Xuzong Chen
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  ABSTRACT: Manipulation of the quantum state by the Majorana transition in spinor BEC system has been realized by altering the rotation frequency of the magnetic field's direction. This kind of manipulation method has no limitation on the transition speed in principle and the system is well closed, which provides a new and superior tool to manipulate quantum states. Using this methord on pulsed atom laser, multicomponent spinor atom laser is generated. We demonstrate that the experiment results are agreed with the theoretical predication.
  01/2007;