Location via proxy:   [ UP ]  
[Report a bug]   [Manage cookies]                

Interaction effects of pseudospin-based magnetic monopoles and kinks in a doped dipolar superlattice gas

Xiang Gao, Shao-Jun Li, Shou-Long Chen, Xue-Ting Fang, Qian-Ru Zhu, Xing Deng, Lushuai Cao, Peter Schmelcher, and Zhong-Kun Hu
Phys. Rev. A 105, 053308 – Published 20 May 2022
PDFHTMLExport Citation
Abstract
Authors
Article Text
  • INTRODUCTION
  • SETUP AND PSEUDOSPIN MAPPING
  • INTERACTION EFFECTS BETWEEN THE NM AND…
  • DISCUSSION AND OUTLOOK
  • ACKNOWLEDGMENTS
  • APPENDICES
    • References

    Abstract

    Magnetic monopoles and kinks are topological excitations that have been extensively investigated in quantum spin systems, but usually, they are studied in different setups. We explore the conditions for the coexistence and interaction effects of these quasiparticles in the pseudospin chain of an atomic dipolar superlattice gas. In this chain, the magnetic kink is the intrinsic quasiparticle, and the particle (hole) defect takes over the role of the north (south) magnetic monopole, exerting monopolar magnetic fields on neighboring spins. A binding effect between the monopole and kink is revealed, which renormalizes the dispersion of the kink. The corresponding dynamical antibinding process is observed and arises due to the kink-antikink annihilation. The rich interaction effects of the two quasiparticles could stimulate corresponding investigations in bulk spin systems.

    • Figure
    • Figure
    • Figure
    • Figure
    • Figure
    • Figure
    • Figure
    3 More
    • Received 30 November 2021
    • Revised 10 April 2022
    • Accepted 11 April 2022

    DOI:https://doi.org/10.1103/PhysRevA.105.053308

    ©2022 American Physical Society

    Physics Subject Headings (PhySH)

    1. Research Areas
    Cold gases in optical latticesDipolar gasesQuantum simulationQuasiparticles & collective excitations
    1. Physical Systems
    1-dimensional spin chainsLattice gasesUltracold gases
    Atomic, Molecular & Optical

    Authors & Affiliations

    Xiang Gao1, Shao-Jun Li1, Shou-Long Chen1, Xue-Ting Fang1, Qian-Ru Zhu1, Xing Deng1, Lushuai Cao1,*, Peter Schmelcher2,3, and Zhong-Kun Hu1,†

    • 1MOE Key Laboratory of Fundamental Physical Quantities Measurement and Hubei Key Laboratory of Gravitation and Quantum Physics, PGMF and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
    • 2Zentrum für optische Quantentechnologien, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
    • 3The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany

    • *lushuaïcao@hust.edu.cn
    • †zkhu@hust.edu.cn

    Article Text (Subscription Required)

    Click to Expand

    References (Subscription Required)

    Click to Expand
    Issue

    Vol. 105, Iss. 5 — May 2022

    Reuse & Permissions
    Access Options
    Author publication services for translation and copyediting assistance advertisement

    Authorization Required

    Log In
    Other Options
    ×

    Images

    • Figure 1
      Figure 1

      (a) The pseudospin chain based on the DSG system. The NM and SM are sketched with the dark and light blue balls, respectively. The transparent orange and dark and light blue arrows refer to the ABM and the monopolar magnetic fields around the NM and SM, respectively. (b) The polarization of neighboring spins around a localized NM, in terms of 〈σ̂x〉 (solid lines) and 〈σ̂z〉 (dashed lines). The spin polarization is also explicitly shown at the bottom. (c) The dynamical process of the pair excitation, the tunneling of the NM and SM, and the spin flipping along the tunneling are shown.

      Reuse & Permissions
    • Figure 2
      Figure 2

      (a) The dynamical structure factor S(k,ω) for the 14-site pseudospin chain with d=40J. The frequency interval of ω∈(0.5,36) is removed where the gap between the first two bands lies. The representative basis states contributed to each band are shown to the right of the structure factor plot, where different ferromagnetic domains are emphasized with solid-line steps and the (anti)kinks locate at the edges of the steps. The pink diamonds in the main plot are the band dispersion obtained from the effective single-particle Hamiltonian describing the emergent particle composed of the monopole and kink. (b) The NM-kink correlation for the ground state. (c) The three-body correlation C3 (blue) and four-body correlation C4 (yellow) of the second band.

      Reuse & Permissions
    • Figure 3
      Figure 3

      The dispersions of a bare kink (black dashed line) and the composite quasiparticle for J1=0.1 (blue circles), 0.2 (brown triangles), 0.3 (cyan diamonds), and 0.4 (yellow squares).

      Reuse & Permissions
    • Figure 4
      Figure 4

      (a) Temporal evolution of C3 (blue) and C4 (yellow) during the dynamical process. (b)–(d) The spatial densities of the NM 〈n̂Nα〉 (blue circles), the kink 〈n̂Kα̃〉 (red diamonds), and the antikink 〈n̂Aα̃〉 (purple triangles) at (b) the beginning and (c) and (d) later times marked by gray vertical lines in (a).

      Reuse & Permissions
    • Figure 5
      Figure 5

      Illustration of the pseudospin mapping. (a) The occupation states of the arbitrary cell are mapped to the pseudospin and defect states. (b) The original DSG system (top panel) and the effective doped pseudospin chain (bottom panel).

      Reuse & Permissions
    • Figure 6
      Figure 6

      The polarization effect for different defects for d=3J. (a) The magnetization along the x (black) and z (blue) axes of the undoped spin chain. (b) The NM, (c) SM, and (d) normal magnetic defect cases. The black solid circles and blue diamonds represent 〈σ̂x〉 and 〈σ̂z〉, respectively.

      Reuse & Permissions
    • Figure 7
      Figure 7

      Illustration of squeezed space. (a) The basis without defects. (b) The basis with the single-particle defect at the fifth site. (c) The basis in a squeezed space. (d) The kink-antikink basis.

      Reuse & Permissions
    • Figure 8
      Figure 8

      The proposed setup. The red (black) arrows indicate the intracell (intercell) hopping of spin-polarized fermions in the DSG system. The brown arrows indicate the hopping of fermions in the bath, while the green arrows are the modulation between these two systems.

      Reuse & Permissions
    • Figure 9
      Figure 9

      Dynamical structure factor of the six-site DSG pseudospin chain. (a) SF(k,ω) obtained with the Fourier transform of the time-dependent correlation function. (b) SM(k,ω) originating from the lattice modulation. (c) and (d) The DOSs with ρG (red dashed line), ρF (blue solid line), and ρM (orange solid line).

      Reuse & Permissions
    • Figure 10
      Figure 10

      The interaction strength versus the relative distance between atoms, in units of J and λs, respectively. The panel above plots the double-well superlattice with the same length scale as the relative distance in the main plot to demonstrate that the interaction mainly affects atoms that are nearest neighbors.

      Reuse & Permissions
    ×

    Sign up to receive regular email alerts from Physical Review A

    Log In

    Cancel
    ×

    Search

    Article Lookup

    Paste a citation or DOI
    Enter a citation
    ×