A disordered insulator in an optical lattice

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Abstract

Disorder can profoundly affect the transport properties of a wide range of quantum materials. At present, significant disagreement exists regarding features of the disordered Bose–Hubbard model, which is used to study disorder in strongly correlated bosonic systems1,2. Here, by measuring transport3 in a disordered optical lattice4, we discover a disorder-induced superfluid-to-insulator transition in this system, in quantitative agreement with a predicted superfluid–Bose-glass transition from recent numerical simulations5. Both the superfluid-to-insulator transition and correlated changes in the atomic quasimomentum distribution—which verify a simple model for the interplay of disorder and interactions in this system—are phenomena new to the unit-filling regime explored in this work. We find that increasing disorder strength generically leads to greater dissipation, excluding predictions of a disorder-induced or ‘re-entrant’ superfluid. Whereas the absence of a re-entrant superfluid may be explained by finite temperature, the measured bounds on entropy strongly constrain theory.

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Figure 1: Effect of disorder on transport.
Figure 2: Effect of disorder on atomic quasimomentum distribution.
Figure 3: Bounds on entropy per particle.

References

  1. 1

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

  2. 2

    Sanchez-Palencia, L. & Lewenstein, M. Disordered quantum gases under control. Nature Phys. 6, 87–95 (2010).

  3. 3

    McKay, D., White, M., Pasienski, M. & DeMarco, B. Phase-slip-induced dissipation in an atomic Bose–Hubbard system. Nature 453, 76–79 (2008).

  4. 4

    White, M. et al. Strongly interacting bosons in a disordered optical lattice. Phys. Rev. Lett. 102, 055301 (2009).

  5. 5

    Gurarie, V., Pollet, L., Prokof’ev, N. V., Svistunov, B. V. & Troyer, M. Phase diagram of the disordered Bose–Hubbard model. Phys. Rev. B 80, 214519 (2009).

  6. 6

    Trivedi, N. in Proc. of the 20th International Workshop on Condensed Matter Theories Vol. 12 141–157 (Plenum Press, 1997).

  7. 7

    Bissbort, U. & Hofstetter, W. Stochastic mean-field theory for the disordered Bose–Hubbard model. Europhys. Lett. 86, 50007 (2009).

  8. 8

    Wu, J. & Phillips, P. Minimal model for disorder-induced missing moment of inertia in solid 4He. Phys. Rev. B 78, 014515 (2008).

  9. 9

    Pollet, L., Prokof’ev, N. V., Svistunov, B. V. & Troyer, M. Absence of a direct superfluid to Mott insulator transition in disordered Bose systems. Phys. Rev. Lett. 103, 140402 (2009).

  10. 10

    Kruger, F., Wu, J. & Phillips, P. Anomalous suppression of the Bose glass at commensurate fillings in the disordered Bose–Hubbard model. Phys. Rev. B 80, 094526 (2009).

  11. 11

    Giamarchi, T. & Schulz, H. J. Localization and interaction in one-dimensional quantum fluids. Europhys. Lett. 3, 1287–1293 (1987).

  12. 12

    Fallani, L., Lye, J. E., Guarrera, V., Fort, C. & Inguscio, M. Ultracold atoms in a disordered crystal of light: Towards a Bose glass. Phys. Rev. Lett. 98, 130404 (2007).

  13. 13

    Roscilde, T. Bosons in one-dimensional incommensurate superlattices. Phys. Rev. A 77, 063605 (2008).

  14. 14

    Damski, B., Zakrzewski, J., Santos, L., Zoller, P. & Lewenstein, M. Atomic Bose and Anderson glasses in optical lattices. Phys. Rev. Lett. 91, 080403 (2003).

  15. 15

    Lye, J. E. et al. Bose–Einstein condensate in a random potential. Phys. Rev. Lett. 95, 070401 (2005).

  16. 16

    Chen, Y. P. et al. Phase coherence and superfluid–insulator transition in a disordered Bose–Einstein condensate. Phys. Rev. A 77, 033632 (2008).

  17. 17

    Clement, D. et al. Suppression of transport of an interacting elongated Bose–Einstein condensate in a random potential. Phys. Rev. Lett. 95, 170409 (2005).

  18. 18

    Schulte, T. et al. Routes towards Anderson-like localization of Bose–Einstein condensates in disordered optical lattices. Phys. Rev. Lett. 95, 170411 (2005).

  19. 19

    Billy, J. et al. Direct observation of Anderson localization of matter waves in a controlled disorder. Nature 453, 891–894 (2008).

  20. 20

    Roati, G. et al. Anderson localization of a non-interacting Bose–Einstein condensate. Nature 453, 895–898 (2008).

  21. 21

    DeMarco, B., Lannert, C., Vishveshwara, S. & Wei, T-C. Structure and stability of Mott-insulator shells of bosons trapped in an optical lattice. Phys. Rev. A 71, 063601 (2005).

  22. 22

    Delande, D. & Zakrzewski, J. Compression as a tool to detect Bose glass in a cold atomic gas. Phys. Rev. Lett. 102, 085301 (2009).

  23. 23

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

  24. 24

    McKay, D., White, M. & DeMarco, B. Lattice thermodynamics for ultra-cold atoms. Phys. Rev. A 79, 063605 (2009).

  25. 25

    Krauth, W., Trivedi, N. & Ceperley, D. Superfluid–insulator transition in disordered boson systems. Phys. Rev. Lett. 67, 2307–2310 (1991).

  26. 26

    Scalettar, R. T., Batrouni, G. G. & Zimanyi, G. T. Localization in interacting, disordered, Bose systems. Phys. Rev. Lett. 66, 3144–3147 (1991).

  27. 27

    Lu, X. & Yu, Y. Finite-temperature effects on the number fluctuation of ultracold atoms across the superfluid-to-Mott-insulator transition. Phys. Rev. A 74, 063615 (2006).

  28. 28

    Freericks, J. K. & Monien, H. Strong-coupling expansions for the pure and disordered Bose–Hubbard model. Phys. Rev. B 53, 2691–2700 (1996).

  29. 29

    Catani, J. et al. Entropy exchange in a mixture of ultracold atoms. Phys. Rev. Lett. 103, 140401 (2009).

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Acknowledgements

This work was supported by the DARPA OLE program (ARO award W911NF-08-1-0021), the Sloan Foundation and the National Science Foundation (award 0448354). D.M. acknowledges support from NSERC.

Author information

M.P., M.W., D.M. and B.D. conceived and designed the experiments. M.P., D.M. and B.D. analysed the data, which were acquired by M.P.

Correspondence to B. DeMarco.

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The authors declare no competing financial interests.

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Pasienski, M., McKay, D., White, M. et al. A disordered insulator in an optical lattice. Nature Phys 6, 677–680 (2010) doi:10.1038/nphys1726

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