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.

  • Letter
  • Published:

Vortex-like excitations and the onset of superconducting phase fluctuation in underdoped La2-xSrxCuO4

Nature volume 406, pages 486–488 (2000)Cite this article

Abstract

Two general features of a superconductor, which appear at the critical temperature, are the formation of an energy gap and the expulsion of magnetic flux (the Meissner effect). In underdoped copper oxides, there is strong evidence that an energy gap (the pseudogap1) opens up at a temperature significantly higher than the critical temperature (by 100–220 K). Certain features of the pseudogap suggest that it is closely related to the gap that appears at the critical temperature (for example, the variation of the gap magnitudes around the Fermi surface and their maximum amplitudes are very similar2,3). However, the Meissner effect is absent in the pseudogap state. The nature of the pseudogap state, and its relation (if any) to the superconducting state are central issues in understanding copper oxide superconductivity. Recent evidence suggests that, in the underdoped regime, the Meissner state is destroyed above the critical temperature by strong phase fluctuations1,4,5,6,7 (as opposed to a vanishing of the superfluid density). Here we report evidence for vortices (or vortex-like excitations) in La2-xSrxCuO4 at temperatures significantly above the critical temperature. A thermal gradient is applied to the sample in a magnetic field. Vortices are detected by the large transverse electric field produced as they diffuse down the gradient (the Nernst effect). We find that the Nernst signal is anomalously enhanced at temperatures as high as 150 K.

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

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

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

Figure 1: Nernst signals.
Figure 2: Log–log plot of the anomalous part of the Nernst coefficient.
Figure 3: Nernst coefficients versus T.
Figure 4: Contour plot of (ν - νn) versus x in the phase diagram of LSCO.

Similar content being viewed by others

References

  1. Timusk, T. & Statt, B. The pseudogap in high-temperature superconductors: an experimental survey. Rep. Prog. Phys. 62, 61–122 (1999).

    Article  ADS  CAS  Google Scholar 

  2. Loeser, A. G. et al. Excitation gap in the normal state of Bi2Sr 2CaCu2O8+δ. Science 273, 325–329 (1996).

    Article  ADS  CAS  Google Scholar 

  3. Ding, H. et al. Spectroscopic evidence for a pseudogap in the normal state of underdoped high-Tc superconductors. Nature 382 , 51–54 (1996).

    Article  ADS  CAS  Google Scholar 

  4. Emery, V. J. & Kivelson, S. A. Importance of phase fluctuations in superconductors with small superfluid density. Nature 374, 434–437 (1995).

    Article  ADS  CAS  Google Scholar 

  5. Norman, M., Randeria, M., Ding, H. & Campuzano, J. C. Phenomenology of the low-energy spectral function in high-Tc superconductors. Phys. Rev. B 57, 11093– 11096 (1998).

    Article  ADS  Google Scholar 

  6. Lee, P. A. & Wen, X. G. Unusual superconducting state of underdoped cuprates. Phys. Rev. Lett. 78, 4111–4114 (1997).

    Article  ADS  CAS  Google Scholar 

  7. Corson, J., Mallozzi, R., Orenstein, J., Eckstein, J. N. & Bozovic, I. Vanishing of phase coherence in underdoped Bi2Sr2CaCu2O8+δ. Nature 398, 221–223 (1999).

    Article  ADS  CAS  Google Scholar 

  8. Ambegaokar, V., Halperin, B. I., Nelson, D. R. & Siggia, E. D. Dynamics of superfluid films. Phys. Rev. B 20, 1806–1826 (1980).

    Article  ADS  Google Scholar 

  9. Hagen, S. J., Lobb, C. J., Greene, R. L., Forrester, M. G. & Talvacchio, J. Flux-flow Nernst effect in epitaxial YBa2Cu3O7. Phys. Rev. B 42, 6777–6780 (1990).

    Article  ADS  CAS  Google Scholar 

  10. Ri, H. C. et al. Nernst, Seebeck, and Hall effect in the mixed state of YBa 2Cu3O7+δ and Bi2Sr2CaCu 2O8+δ—a comparative study. Phys. Rev. B 50, 3312–3329 ( 1994).

    Article  ADS  CAS  Google Scholar 

  11. Clayhold, J. A., Linnen, A. W. Jr, Chen, F. & Chu, C. W. Normal-state Nernst effect in a Tl2Ba2CaCu2O 8+δ. Phys. Rev. B 50, 4252– 4255 (1994).

    Article  ADS  CAS  Google Scholar 

  12. Sondheimer, E. H. The theory of the galvanomagnetic and thermomagnetic effects in metals. Proc. R. Soc. Lond. A 193, 484–512 (1948).

    Article  ADS  Google Scholar 

  13. Tranquada, J. M., Sternlieb, B. J., Axe, J. D., Nakamura, Y. & Uchida, S. Evidence for stripe correlations of spins and holes in copper oxide superconductors. Nature 375, 561–563 (1995).

    Article  ADS  Google Scholar 

  14. Takagi, H., Ido, T., Ishibashi, S., Uota, M. & Uchida, S. Superconductor-to-nonsuperconductor transition in (La 1-xSrx)2CuO4 as investigated by transport and magnetic measurements. Phys. Rev. B 40, 2254–2261 (1989).

    Article  ADS  CAS  Google Scholar 

  15. Loram, J. W., Mirza, K. A., Cooper, J. R., Athanassopoulou, N. & Liang, W. Y. in Proc. 10th HTS Anniversary Workshop on Physics, Materials and Applications (eds Batlogg, B., Chu, C. W., Chu, W. K., Gubser, D. U. & Muller, K. A.) 341 (World Scientific, Singapore, 1996).

    Google Scholar 

Download references

Acknowledgements

Comments by P. W. Anderson, P. A. Lee and Z. Weng are acknowledged. The research is supported by the US Office of Naval Research and the US National Science Foundation. N.P.O. and S.U. acknowledge support from the New Energy and Industrial Technology Development Organization, Japan.

Author information

Author notes

  1. Z. A. Xu

    Present address: Department of Physics, Zhejiang University, Hangzhou, 310027, China

Authors and Affiliations

  1. Joseph Henry Laboratories of Physics, Princeton University, Princeton, 08544, New Jersey, USA

    Z. A. Xu, N. P. Ong & Y. Wang

  2. School of Frontier Sciences, University of Tokyo, Yayoi 2-11-16, Bunkyo-ku, 113-8656, Tokyo, Japan

    T. Kakeshita & S. Uchida

Authors
  1. Z. A. Xu
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. N. P. Ong
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Y. Wang
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. T. Kakeshita
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. S. Uchida
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to N. P. Ong.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Xu, Z., Ong, N., Wang, Y. et al. Vortex-like excitations and the onset of superconducting phase fluctuation in underdoped La2-xSrxCuO4. Nature 406, 486–488 (2000). https://doi.org/10.1038/35020016

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/35020016

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

Advanced 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