Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Quantum simulation of antiferromagnetic spin chains in an optical lattice

Abstract

Understanding exotic forms of magnetism in quantum mechanical systems is a central goal of modern condensed matter physics, with implications for systems ranging from high-temperature superconductors to spintronic devices. Simulating magnetic materials in the vicinity of a quantum phase transition is computationally intractable on classical computers, owing to the extreme complexity arising from quantum entanglement between the constituent magnetic spins. Here we use a degenerate Bose gas of rubidium atoms confined in an optical lattice to simulate a chain of interacting quantum Ising spins as they undergo a phase transition. Strong spin interactions are achieved through a site-occupation to pseudo-spin mapping. As we vary a magnetic field, quantum fluctuations drive a phase transition from a paramagnetic phase into an antiferromagnetic phase. In the paramagnetic phase, the interaction between the spins is overwhelmed by the applied field, which aligns the spins. In the antiferromagnetic phase, the interaction dominates and produces staggered magnetic ordering. Magnetic domain formation is observed through both in situ site-resolved imaging and noise correlation measurements. By demonstrating a route to quantum magnetism in an optical lattice, this work should facilitate further investigations of magnetic models using ultracold atoms, thereby improving our understanding of real magnetic materials.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Spin model and its phase diagram.
Figure 2: Tilted Hubbard model and mapping to spin model.
Figure 3: Probing the paramagnet to antiferromagnet phase transition.
Figure 4: Effect of harmonic confinement.
Figure 5: Site-resolved transition in near-homogeneous Ising model.
Figure 6: Dynamics of antiferromagnetic domain formation.

Similar content being viewed by others

References

  1. Balents, L. Spin liquids in frustrated magnets. Nature 464, 199–208 (2010)

    Article  ADS  CAS  Google Scholar 

  2. Binder, K. & Young, A. P. Spin glasses: experimental facts, theoretical concepts, and open questions. Rev. Mod. Phys. 58, 801–976 (1986)

    Article  ADS  CAS  Google Scholar 

  3. Kitaev, A. Anyons in an exactly solved model and beyond. Ann. Phys. 321, 2–111 (2006)

    Article  ADS  MathSciNet  CAS  Google Scholar 

  4. Sachdev, S. Quantum Phase Transitions (Cambridge Univ. Press, 2001)

    MATH  Google Scholar 

  5. Anderson, P. W. The resonating valence bond state in La2CuO4 and superconductivity. Science 235, 1196–1198 (1987)

    Article  ADS  CAS  Google Scholar 

  6. Rüegg, C. et al. Quantum magnets under pressure: controlling elementary excitations in TlCuCl3 . Phys. Rev. Lett. 100, 205701 (2008)

    Article  ADS  Google Scholar 

  7. Coldea, R. et al. Quantum criticality in an Ising chain: experimental evidence for emergent E8 symmetry. Science 327, 177–180 (2010)

    Article  ADS  CAS  Google Scholar 

  8. Lewenstein, M. et al. Ultracold atomic gases in optical lattices: mimicking condensed matter physics and beyond. Adv. Phys. 56, 243–379 (2007)

    Article  ADS  Google Scholar 

  9. Bloch, I., Dalibard, J. & Zwerger, W. Many-body physics with ultracold gases. Rev. Mod. Phys. 80, 885–964 (2008)

    Article  ADS  CAS  Google Scholar 

  10. Greiner, M., Mandel, O., Esslinger, E., Haensch, T. W. & Bloch, I. Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms. Nature 415, 39–44 (2002)

    Article  ADS  CAS  Google Scholar 

  11. Sachdev, S. Quantum magnetism and criticality. Nature Phys. 4, 173–185 (2008)

    Article  ADS  CAS  Google Scholar 

  12. Zhang, X., Hung, C.-L., Tung, S.-K., Gemelke, N. & Chin, C. Exploring quantum criticality based on ultracold atoms in optical lattices. Preprint at 〈http://arXiv.org/abs/1101.0284〉 (2010)

  13. Hung, C.-L., Zhang, X., Gemelke, N. & Chin, C. Observation of scale invariance and universality in two-dimensional Bose gases. Nature 470, 236–239 (2011)

    Article  ADS  CAS  Google Scholar 

  14. Bakr, W. S., Gillen, J. I., Peng, A., Foelling, S. & Greiner, M. A quantum gas microscope for detecting single atoms in a Hubbard-regime optical lattice. Nature 462, 74–77 (2009)

    Article  ADS  CAS  Google Scholar 

  15. Bakr, W. S. et al. Probing the superfluid-to-Mott insulator transition at the single-atom level. Science 329, 547–550 (2010)

    Article  ADS  CAS  Google Scholar 

  16. Sherson, J. F. et al. Single-atom-resolved fluorescence imaging of an atomic Mott insulator. Nature 467, 68–72 (2010)

    Article  ADS  CAS  Google Scholar 

  17. Weitenberg, C. et al. Single-spin addressing in an atomic Mott insulator. Nature 471, 319–324 (2011)

    Article  ADS  CAS  Google Scholar 

  18. Jo, G. et al. Itinerant ferromagnetism in a Fermi gas of ultracold atoms. Science 325, 1521–1524 (2009)

    Article  ADS  CAS  Google Scholar 

  19. Friedenauer, A., Schmitz, H., Glueckert, J. T., Porras, D. & Schaetz, T. Simulating a quantum magnet with trapped ions. Nature Phys. 4, 757–761 (2008)

    Article  ADS  CAS  Google Scholar 

  20. Kim, K. et al. Quantum simulation of frustrated Ising spins with trapped ions. Nature 465, 590–593 (2010)

    Article  ADS  CAS  Google Scholar 

  21. Ni, K.-K. et al. A high phase-space-density gas of polar molecules. Science 322, 231–235 (2008)

    Article  ADS  CAS  Google Scholar 

  22. Saffman, M. & Walker, T. G. Quantum information with Rydberg atoms. Rev. Mod. Phys. 82, 2313–2363 (2010)

    Article  ADS  CAS  Google Scholar 

  23. Lukin, M. D. et al. Dipole blockade and quantum information processing in mesoscopic atomic ensembles. Phys. Rev. Lett. 87, 037901 (2001)

    Article  ADS  CAS  Google Scholar 

  24. Büchler, H. P. et al. Strongly correlated 2D quantum phases with cold polar molecules: controlling the shape of the interaction potential. Phys. Rev. Lett. 98, 060404 (2007)

    Article  ADS  Google Scholar 

  25. Weimer, H., Müller, M. & Lesanovsky, I. A Rydberg quantum simulator. Nature Phys. 6, 382–388 (2010)

    Article  ADS  CAS  Google Scholar 

  26. Lee, P. J. et al. Sublattice addressing and spin-dependent motion of atoms in a double-well lattice. Phys. Rev. Lett. 99, 020402 (2007)

    Article  ADS  CAS  Google Scholar 

  27. Soltan-Panahi, P. et al. Multi-component quantum gases in spin-dependent hexagonal lattices. Nature Phys. advance online publication. 10.1038/nphys1916 (13 February 2011)

  28. Fölling, S. et al. Direct observation of second-order atom tunnelling. Nature 448, 1029–1032 (2007)

    Article  ADS  Google Scholar 

  29. Fisher, M. P. A., Weichman, P. B., Grinstein, G. & Fisher, D. S. Boson localization and the superfluid-insulator transition. Phys. Rev. B 40, 546–570 (1989)

    Article  ADS  CAS  Google Scholar 

  30. Jaksch, D., Bruder, C., Cirac, J. I., Gardiner, C. W. & Zoller, P. Cold bosonic atoms in optical lattices. Phys. Rev. Lett. 81, 3108–3111 (1998)

    Article  ADS  CAS  Google Scholar 

  31. Sachdev, S., Sengupta, K. & Girvin, S. M. Mott insulators in strong electric fields. Phys. Rev. B 66, 075128 (2002)

    Article  ADS  Google Scholar 

  32. Duan, L. M., Demler, E. & Lukin, M. D. Controlling spin exchange interactions of ultracold atoms in optical lattices. Phys. Rev. Lett. 91, 090402 (2003)

    Article  ADS  Google Scholar 

  33. Trotzky, S. et al. Time-resolved observation and control of superexchange interactions with ultracold atoms in optical lattices. Science 319, 295–299 (2008)

    Article  ADS  CAS  Google Scholar 

  34. Capogrosso-Sansone, B., Soeyler, S. G., Prokof'ev, N. V. & Svistunov, B. V. Critical entropies for magnetic ordering in bosonic mixtures on a lattice. Phys. Rev. A 81, 053622 (2010)

    Article  ADS  Google Scholar 

  35. Weld, D. M. et al. Spin gradient thermometry for ultracold atoms in optical lattices. Phys. Rev. Lett. 103, 245301 (2009)

    Article  ADS  Google Scholar 

  36. Medley, P., Weld, D., Miyake, H., Pritchard, D. E. & Ketterle, W. Spin gradient demagnetization cooling of ultracold atoms. Preprint at 〈http://arxiv.org/abs/1006.4674〉 (2010)

  37. McKay, D. & DeMarco, B. Cooling in strongly correlated optical lattices: prospects and challenges. Preprint at 〈http://arxiv.org/abs/1010.0198〉 (2010)

  38. García-Ripoll, J. J., Martin-Delgado, M. A. & Cirac, J. I. Implementation of spin Hamiltonians in optical lattices. Phys. Rev. Lett. 93, 250405 (2004)

    Article  ADS  Google Scholar 

  39. Novotny, M. A. & Landau, D. P. Zero temperature phase diagram for the d = 1 quantum Ising antiferromagnet. J. Magn. Magn. Mater. 54-57, 685–686 (1986)

    Article  ADS  Google Scholar 

  40. Ovchinnikov, A. A., Dmitriev, D. V., Krivnov, V. Y. & Cheranovskii, V. O. Antiferromagnetic Ising chain in a mixed transverse and longitudinal magnetic field. Phys. Rev. B 68, 214406 (2003)

    Article  ADS  Google Scholar 

  41. Imry, Y. & Ma, S.-k. Random-field instability of the ordered state of continuous symmetry. Phys. Rev. Lett. 35, 1399–1401 (1975)

    Article  ADS  CAS  Google Scholar 

  42. Dziarmaga, J. Dynamics of a quantum phase transition in the random Ising model: logarithmic dependence of the defect density on the transition rate. Phys. Rev. B 74, 064416 (2006)

    Article  ADS  Google Scholar 

  43. Vidal, G., Latorre, J. I., Rico, E. & Kitaev, A. Entanglement in quantum critical phenomena. Phys. Rev. Lett. 90, 227902 (2003)

    Article  ADS  CAS  Google Scholar 

  44. Altman, E., Demler, E. & Lukin, M. D. Probing many-body states of ultracold atoms via noise correlations. Phys. Rev. A 70, 013603 (2004)

    Article  ADS  Google Scholar 

  45. Fölling, S. et al. Spatial quantum noise interferometry in expanding ultracold atom clouds. Nature 434, 481–484 (2005)

    Article  ADS  Google Scholar 

  46. Sørensen, A. S. et al. Adiabatic preparation of many-body states in optical lattices. Phys. Rev. A 81, 061603 (2010)

    Article  ADS  Google Scholar 

  47. Bañuls, M. C., Cirac, J. I. & Hastings, M. B. Strong and weak thermalization of infinite nonintegrable quantum systems. Phys. Rev. Lett. 106, 050405 (2011)

    Article  ADS  Google Scholar 

  48. Plötz, P., Schlagheck, P. & Wimberger, S. Effective spin model for interband transport in a Wannier-Stark lattice system. Eur. Phys. J. D 10.1140/epjd/e2010-10554-7 (2010)

  49. Pielawa, S., Kitagawa, T., Berg, E. & Sachdev, S. Correlated phases of bosons in tilted, frustrated lattices. Preprint at 〈http://arxiv.org/abs/1101.2897〉 (2010)

Download references

Acknowledgements

We thank E. Demler, W. Ketterle, T. Kitagawa, M.D. Lukin, S. Pielawa and S. Sachdev for discussions. This work was supported by the Army Research Office DARPA OLE programme, an AFOSR MURI programme, and by grants from the NSF.

Author information

Authors and Affiliations

Authors

Contributions

All authors contributed to the construction of the experiment, the collection and analysis of the data, and the writing of the manuscript.

Corresponding author

Correspondence to Markus Greiner.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

The file contains Supplementary Discussions, Supplementary Table 1, Supplementary Figures 1-3 with legends and additional references. (PDF 547 kb)

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Cite this article

Simon, J., Bakr, W., Ma, R. et al. Quantum simulation of antiferromagnetic spin chains in an optical lattice. Nature 472, 307–312 (2011). https://doi.org/10.1038/nature09994

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature09994

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing