Abstract
High-temperature superconductivity is known to involve the pairing of charge carriers, but the precise nature of these carriers and the mechanism of their pairing remain unclear. The copper oxides are known to exhibit a strong Jahn–Teller effect — in which spontaneous lattice distortions remove the degeneracy of the electronic ground state — and it has been suggested that the charge carriers are Jahn–Teller polarons (bare charge carriers accompanied by local lattice distortions). In fact, the demonstration1 that a strong Jahn–Teller effect can lead to the formation of such polarons led to the original discovery of high-temperature superconductivity2. Still, direct evidence that Jahn–Teller polarons exist in the superconducting state of the copper oxides has been lacking, although some indirect evidence comes from their recent discovery3 in the structurally similar but non-superconducting manganite La1–xCaxMnO3. Here we report the results of magnetization and thermal expansion measurements on samples of the copper oxide superconductor La2–xSrxCuO4 which characterize the oxygen-isotope effects on the carrier density and on the in-plane penetration depth. We find a negligible isotope effect on the former, but a large effect on the latter. Specific quantitative features of the results show that polaronic charge carriers exist and condense into Cooper pairs in the copper oxide superconductors.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Höck, K.-H., Nickisch, H. & Thomas, H. Helv. Phys. Acta. 56, 237–243 (1983).
Bednorz, J. G. & Müller, K. A. Z. Phys. B 64, 189–193 (1986).
Zho, G. M., Conder, K., Keller, H. & Müller, K. A. Nature 381, 676–678 (1996).
Proc. Int. Workshop on Anharmonic Properties of High-Tc Cuprates (eds Mihailowic, D., Ruani, G., Kaldis, E. & Müller, K. A.) 118–146 (World Scientific, Singapore, 1994).
Bi, X. X. & Eklund, P. C. Phys. Rev. Lett. 70, 2625–2628 (1993).
Alexandrov, A. S. & Mott, N. F. Int. J. Mod. Phys. 8, 2075–2109 (1994).
Crawford, M. K., Kunchur, M. N., Farneth, W. E., McCarron, E. M. & Poon, S. J. Phys. Rev. B 41, 282–287 (1990).
Crawford, M. K., Farneth, W. E., McCarron, E. M. Harlow, R. L. & Moudden, A. H. Science 250, 1390–1394 (1990).
Ronay, M., Frisch, M. A. & McGuire, T. R. Phys. Rev. B 45, 355–360 (1992).
Franck, J. P., Harker, S. & Brewer, J. H. Phys. Rev. Lett. 71, 283–286 (1993).
Bornemann, H. J. & Morris, D. E. Phys. Rev. B 44, 5322–5325 (1991).
Zhao, G. M., Singh, K. K., Sinha, A. P. B. & Morris, D. E. Phys. Rev. B 52, 6840–6844 (1995).
Shoenberg, D. Proc. R. Soc. Lond. A 175, 49–70 (1940).
Kogan, V. G., Fang, M. M. & Mitra, S. Phys. Rev. B 38, 11958–11961 (1988).
Uemura, Y. J. et al. Phys. Rev. Lett. 62, 2317–2320 (1989).
Sarrao, J. L. et al. Phys. Rev. B 50, 13125–13131 (1994).
Okajima, Y., Hashimoto, S. & Yamaya, K. Physica C 235–240, 1317–1318 (1994).
Kato, M., Maeno, Y. & Fujita, T. Physica C 152, 116–120 (1988).
Dabrowski, B. et al. Phys. Rev. Lett. 76, 1348–1351 (1996).
Fiory, A. T. et al. Phys. Rev. Lett. 65, 3441–3444 (1990).
Shibauchi, T. et al. Phys. Rev. Lett. 72, 2263–2266 (1994).
Ekino, T. M., Fujii, H. & Akimitsu, J. Physica C 235–240, 1899–1900 (1994).
Chen, X. K., Irwin, J. C., Trodahl, H. J., Kimura, T. & Kishio, K. Phys. Rev. Lett. 73, 3290–3293 (1994).
Ding, H. et al. Nature 382, 51–54 (1996).
Loram, J. W., Mirza, K. A., Wade, J. M., Cooper, J. R. & Liang, W. Y. Physica C 235–240, 134–137 (1994).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Zhao, Gm., Hunt, M., Keller, H. et al. Evidence for polaronic supercarriers in the copper oxide superconductors La2–xSrxCuO4. Nature 385, 236–239 (1997). https://doi.org/10.1038/385236a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/385236a0
This article is cited by
-
Unravelling a new many-body large-hole polaron in a transition metal oxide that promotes high photocatalytic activity
NPG Asia Materials (2022)
-
Polarons in materials
Nature Reviews Materials (2021)
-
Pre-formed Cooper pairs in copper oxides and LaAlO3—SrTiO3 heterostructures
Nature Physics (2020)
-
Cooperative origin of proton pair diffusivity in yttrium substituted barium zirconate
Communications Physics (2020)
-
Specific criteria for BCS-type cuprate superconductivity and peculiar isotope effects on the critical superconducting transition temperature
Pramana (2020)
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.
