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:

Probing quantum and thermal noise in an interacting many-body system

Abstract

The probabilistic character of the measurement process is one of the most puzzling and fascinating aspects of quantum mechanics. In many-body systems quantum-mechanical noise reveals non-local correlations of the underlying many-body states. Here, we provide a complete experimental analysis of the shot-to-shot variations of interference-fringe contrast for pairs of independently created one-dimensional Bose condensates. Analysing different system sizes, we observe the crossover from thermal to quantum noise, reflected in a characteristic change in the distribution functions from poissonian to Gumbel type, in excellent agreement with theoretical predictions on the basis of the Luttinger-liquid formalism. We present the first experimental observation of quasi-long-range order in one-dimensional atomic condensates, which is a hallmark of quantum fluctuations in one-dimensional systems. Furthermore, our experiments constitute the first analysis of the full distribution of quantum noise in an interacting many-body system.

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: Experimental set-up and observed interference patterns.
Figure 2: Analysis of the observed interference patterns.
Figure 3: Length dependence of the average contrast.
Figure 4: Distribution functions of the measured interference contrasts for different lengths L.

Similar content being viewed by others

References

  1. Wheeler, J. & Zurek, W. Quantum Theory and Measurement (Princeton Univ. Press, Princeton, 1984).

    Google Scholar 

  2. Gardiner, C. W. & Zoller, P. Quantum Noise (Springer, Berlin, 2004).

    MATH  Google Scholar 

  3. Levitov, L. S. in Quantum Noise in Mesoscopic Systems (ed. Nazarov, Yu. V.) (Kluwer, Dordrecht, 2007).

    Google Scholar 

  4. Sukhorukov, E. V. et al. Conditional statistics of electron transport in interacting nanoscale conductors. Nature Phys. 3, 243–247 (2007).

    Article  ADS  Google Scholar 

  5. Samuelsson, P., Sukhorukov, E. V. & Büttiker, M. Two-particle Aharonov–Bohm effect and entanglement in the electronic Hanbury Brown–Twiss setup. Phys. Rev. Lett. 92, 026805 (2004).

    Article  ADS  Google Scholar 

  6. Neder, I. et al. Interference between two indistinguishable electrons from independent sources. Nature 448, 333–337 (2007).

    Article  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

  9. Rom, T. et al. Free fermion antibunching in a degenerate atomic Fermi gas released from an optical lattice. Nature 444, 733–736 (2006).

    Article  ADS  Google Scholar 

  10. Greiner, M., Regal, C. A., Stewart, J. T. & Jin, D. S. Probing pair-correlated fermionic atoms through correlations in atom shot noise. Phys. Rev. Lett. 94, 110401 (2005).

    Article  ADS  Google Scholar 

  11. Öttl, A., Ritter, S., Köhl, M. & Esslinger, T. Correlations and counting statistics of an atom laser. Phys. Rev. Lett. 95, 090404 (2005).

    Article  ADS  Google Scholar 

  12. Schellekens, M. et al. Hanbury Brown Twiss effect for ultracold quantum gases. Science 310, 638–651 (2005).

    Article  ADS  Google Scholar 

  13. Jeltes, T. et al. Comparison of the Hanbury Brown–Twiss effect for bosons and fermions. Nature 445, 402–405 (2007).

    Article  ADS  Google Scholar 

  14. Donner, T. et al. Critical behavior of a trapped interacting Bose gas. Science 315, 1556–1558 (2007).

    Article  ADS  Google Scholar 

  15. Richard, S. et al. Momentum spectroscopy of 1d phase fluctuations in Bose–Einstein condensates. Phys. Rev. Lett. 91, 010405 (2003).

    Article  ADS  Google Scholar 

  16. Hadzibabic, Z., Krüger, P., Cheneau, M., Battelier, B. & Dalibard, J. Berezinskii–Kosterlitz–Thouless crossover in a trapped atomic gas. Nature 441, 1118–1121 (2006).

    Article  ADS  Google Scholar 

  17. Polkovnikov, A., Altman, E. & Demler, E. Interference between independent fluctuating condensates. Proc. Natl Acad. Sci. USA 103, 6125–6129 (2006).

    Article  ADS  Google Scholar 

  18. Gritsev, V., Altman, E., Demler, E. & Polkovnikov, A. Full quantum distribution of contrast in interference experiments between interacting one dimensional Bose liquids. Nature Phys. 2, 705–709 (2006).

    Article  ADS  Google Scholar 

  19. Dettmer, S. et al. Observation of phase fluctuations in elongated Bose–Einstein condensates. Phys. Rev. Lett. 87, 160406 (2001).

    Article  ADS  Google Scholar 

  20. Esteve, J. et al. Observations of density fluctuations in a very elongated Bose gas: From the ideal gas to the quasi-condensate regime. Phys. Rev. Lett. 96, 130403 (2006).

    Article  ADS  Google Scholar 

  21. Tolra, B. L. et al. Observation of reduced three-body recombination in a correlated 1d degenerate Bose gas. Phys. Rev. Lett. 92, 190401 (2004).

    Article  ADS  Google Scholar 

  22. Kinoshita, T., Wenger, T. & Weiss, D. S. Observation of a one-dimensional Tonks–Girardeau gas. Science 305, 1125–1128 (2004).

    Article  ADS  Google Scholar 

  23. Paredes, B. et al. Tonks–Girardeau gas of ultracold atoms in an optical lattice. Nature 429, 277–281 (2004).

    Article  ADS  Google Scholar 

  24. Schumm, T. et al. Matter wave interferometry in a double well on an atom chip. Nature Phys. 1, 57–62 (2005).

    Article  ADS  Google Scholar 

  25. Hofferberth, S., Lesanovsky, I., Fischer, B., Verdu, J. & Schmiedmayer, J. Radio-frequency dressed state potentials for neutral atoms. Nature Phys. 2, 710–716 (2006).

    Article  ADS  Google Scholar 

  26. Lesanovsky, I. et al. Adiabatic radio frequency potentials for the coherent manipulation of matter waves. Phys. Rev. A 73, 033619 (2006).

    Article  ADS  Google Scholar 

  27. Folman, R., Krüger, P., Schmiedmayer, J., Denschlag, J. & Henkel, C. Microscopic atom optics: From wires to an atom chip. Adv. At. Mol. Opt. Phys. 48, 263–356 (2002).

    Article  ADS  Google Scholar 

  28. Fortagh, J. & Zimmermann, C. Magnetic microtraps for ultracold atoms. Rev. Mod. Phys. 79, 235–290 (2007).

    Article  ADS  Google Scholar 

  29. Petrov, D. S., Gangardt, D. M. & Shlyapnikov, G. V. Low-dimensional trapped gases. J. Phys. IV 116, 5–44 (2004).

    Google Scholar 

  30. Bouchoule, I., Kheruntsyan, K. V. & Shlyapnikov, G. V. Interaction-induced crossover versus finite-size condensation in a weakly interacting trapped one-dimensional Bose gas. Phys. Rev. A 75, 031606(R) (2007).

    Article  ADS  Google Scholar 

  31. Imambekov, A., Gritsev, V. & Demler, E. in Proc. 2006 Enrico Fermi Summer School on Ultracold Fermi Gases (eds Inguscio, M., Ketterle, W. & Salomon, C.) (IOS Press, Amsterdam, 2007).

    Google Scholar 

  32. Castin, Y. & Dalibard, J. Relative phase of two Bose–Einstein condensates. Phys. Rev. A 55, 4330–4337 (1997).

    Article  ADS  Google Scholar 

  33. Javanainen, J. & Wilkens, M. Phase and phase diffusion of a split Bose–Einstein condensate. Phys. Rev. Lett. 78, 4675–4678 (1997).

    Article  ADS  Google Scholar 

  34. Leggett, A. J. Bose–Einstein condensation in the alkali gases. Rev. Mod. Phys. 73, 307–356 (2001).

    Article  ADS  Google Scholar 

  35. Popov, V. N. Functional Integrals in Quantum Field Theory and Statistical Physics (Reidel, Dordrecht, 1983).

    Book  Google Scholar 

  36. Haldane, F. Effective harmonic-fluid approach to low-energy properties of one-dimensional quantum fluids. Phys. Rev. Lett. 47, 1840–1843 (1981).

    Article  ADS  Google Scholar 

  37. Giamarchi, T. Quantum Physics in One Dimension (Oxford Univ. Press, Oxford, 2003).

    Book  Google Scholar 

  38. Cazalilla, M. Bosonizing one-dimensional cold atomic gases. J. Phys. B 37, S1–S47 (2004).

    Article  ADS  Google Scholar 

  39. Polkovnikov, A. Shot noise of interference between independent atomic systems. Europhys. Lett. 78, 10006–10010 (2007).

    Article  ADS  Google Scholar 

  40. Gumbel, E. J. Statistics of Extremes (Columbia Univ. Press, New York, 1958).

    Book  Google Scholar 

  41. Imambekov, A., Gritsev, V. & Demler, E. Mapping of Coulomb gases and sine–Gordon models to statistics of random surfaces. Preprint at <http://arxiv.org/abs/cond-mat/0612011> (2006).

  42. Belzig, W., Schroll, C. & Bruder, C. Density correlations in ultracold atomic Fermi gases. Phys. Rev. A 75, 063611 (2007).

    Article  ADS  Google Scholar 

  43. Eckert, K. et al. Quantum non-demolition detection of strongly correlated systems. Nature Phys. 4, 50–54 (2008).

    Article  ADS  Google Scholar 

  44. Cherng, R. & Demler, E. Quantum noise analysis of spin systems realized with cold atoms. New J. Phys. 9, 7 (2007).

    Article  ADS  Google Scholar 

  45. Eckert, K., Zawitkowski, L., Sanpera, A., Lewenstein, M. & Polzik, E. S. Quantum polarization spectroscopy of ultracold spinor gases. Phys. Rev. Lett. 98, 100404 (2007).

    Article  ADS  Google Scholar 

  46. Wildermuth, S. et al. Optimized magneto-optical trap for experiments with ultracold atoms near surfaces. Phys. Rev. A 69, 030901 (2004).

    Article  ADS  Google Scholar 

  47. Hofferberth, S., Fischer, B., Schumm, T., Schmiedmayer, J. & Lesanovsky, I. Ultracold atoms in radio-frequency dressed potentials beyond the rotating-wave approximation. Phys. Rev. A 76, 013401 (2007).

    Article  ADS  Google Scholar 

  48. Olshanii, M. Atomic scattering in presence of an external confinement and a gas of impenetrable bosons. Phys. Rev. Lett. 81, 938–941 (1998).

    Article  ADS  Google Scholar 

  49. Lieb, E. & Liniger, W. Exact analysis of an interacting Bose gas. i. The general solution and the ground state. Phys. Rev. 130, 1605–1616 (1963).

    Article  ADS  MathSciNet  Google Scholar 

  50. Caux, J.-S., Calabrese, P. & Slavnov, N. A. One-particle dynamical correlations in the one-dimensional Bose gas. J. Stat. Mech. 0701, P008 (2007).

    Google Scholar 

Download references

Acknowledgements

We acknowledge financial support from the European Union through the contracts MRTN-CT-2003-505032 (Atom chips), Integrated Project FET/QIPC ‘SCALA’, FWF, NSF, Harvard-MIT CUA, AFOSR, Swiss NSF and MURI. We thank S. Groth for fabricating the atom chip used in the experiments and D. A. Smith for critical reading of the manuscript.

Author information

Authors and Affiliations

Authors

Contributions

S.H. and J.S. collected the data presented in this article. A.I., V.G., and E.D. provided the theoretical models used. All authors contributed to analysis and interpretation of the data and helped in editing the manuscript.

Corresponding author

Correspondence to J. Schmiedmayer.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Hofferberth, S., Lesanovsky, I., Schumm, T. et al. Probing quantum and thermal noise in an interacting many-body system. Nature Phys 4, 489–495 (2008). https://doi.org/10.1038/nphys941

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nphys941

This article is cited by

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