The attempt to understand copper oxide superconductors is complicated by the presence of multiple strong interactions in these systems. Many believe that antiferromagnetism is important for superconductivity, but there has been renewed interest in the possible role of electron–lattice coupling1,2,3,4. The conventional superconductor MgB2 has a very strong electron–lattice coupling, involving a particular vibrational mode (phonon) that was predicted by standard theory and confirmed quantitatively by experiment5. Here we present inelastic scattering measurements that show a similarly strong anomaly in the Cu–O bond-stretching phonon in the copper oxide superconductors La2-xSrxCuO4 (with x = 0.07, 0.15). Conventional theory does not predict such behaviour. The anomaly is strongest in La1.875Ba0.125CuO4 and La1.48Nd0.4Sr0.12CuO4, compounds that exhibit spatially modulated charge and magnetic order, often called stripe order6; it occurs at a wave vector corresponding to the charge order. These results suggest that this giant electron–phonon anomaly, which is absent in undoped and over-doped non-superconductors, is associated with charge inhomogeneity. It follows that electron–phonon coupling may be important to our understanding of superconductivity, although its contribution is likely to be indirect.
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Lanzara, A. et al. Evidence for ubiquitous strong electron-phonon coupling in high-temperature superconductors. Nature 412, 510–514 (2001)
Devereaux, T. P., Cuk, T., Shen, Z.-X. & Nagaosa, N. Anisotropic electron-phonon interaction in the cuprates. Phys. Rev. Lett. 93, 117004 (2004)
Bohnen, K.-P., Heid, R. & Krauss, M. Phonon dispersion and electron-phonon interaction for YBa2Cu3O7 from first-principles calculations. Europhys. Lett. 64, 104–110 (2003)
Falter, C. & Hoffmann, G. A. Nonlocal electron-phonon coupling of ionic charge-fluctuation type and phonon anomalies in high-temperature superconductors. Phys. Rev. B 64, 054516 (2001)
Baron, A. Q. R. et al. Kohn anomaly in MgB2 by inelastic X-ray scattering. Phys. Rev. Lett. 92, 197004 (2004)
Tranquada, J. M. et al. Evidence for stripe correlations of spins and holes in copper oxide superconductors. Nature 375, 561–563 (1995)
Zaanen, J. & Gunnarsson, O. Charged magnetic domain lines and the magnetism of high-Tc oxides. Phys. Rev. B 40, 7391–7394 (1989)
Machida, K. Magnetism in La2CuO4 based compounds. Physica C 158, 192–196 (1989)
Kivelson, S. A. et al. How to detect fluctuating stripes in the high-temperature superconductors. Rev. Mod. Phys. 75, 1201–1241 (2003)
McQueeney, R. J. et al. Anomalous dispersion of LO phonons in La1.85Sr0.15CuO4 at low temperatures. Phys. Rev. Lett. 82, 628–631 (1999)
Chung, J.-H. et al. In-plane anisotropy and temperature dependence of oxygen phonon modes in YBa2Cu3O6.95 . Phys. Rev. B 67, 014517 (2003)
Pintschovius, L. et al. Lattice dynamical studies of HTSC materials. Physica C 185–189, 156–161 (1991)
Tranquada, J. M., Nakajima, K., Braden, M., Pintschovius, L. & McQueeney, R. J. Bond-stretching-phonon anomalies in stripe-ordered La1.69Sr0.31NiO4 . Phys. Rev. Lett. 88, 075505 (2002)
Ito, M. et al. Effects of “stripes” on the magnetic excitation spectra of La1.48Nd0.4Sr0.12CuO4 . J. Phys. Soc. Jpn 72, 1627–1630 (2003)
Fujita, M., Goka, H., Yamada, K., Tranquada, J. M. & Regnault, L. P. Stripe order, depinning, and fluctuations in La1.875Ba0.125CuO4 and La1.875Ba0.075Sr0.050CuO4 . Phys. Rev. B 70, 104517 (2004)
Abbamonte, P. et al. Spatially modulated ‘Mottness’ in La2-xBaxCuO4 . Nature Phys. 1, 155–158 (2005)
Chaplot, S. L., Reichardt, W., Pintschovius, L. & Pyka, N. Common interatomic potential model for the lattice dynamics of several cuprates. Phys. Rev. B 52, 7230–7242 (1995)
Pintschovius, L., Reichardt, W., Kläser, M., Wolf, T. & von Löhneysen, H. Pronounced in-plane anisotropy of phonon anomalies in YBa2Cu3O6.6 . Phys. Rev. Lett. 89, 037001 (2002)
Pintschovius, L. et al. Oxygen phonon branches in YBa2Cu3O7 . Phys. Rev. B 69, 214506 (2004)
Uchiyama, H. et al. Softening of Cu-O bond stretching phonons in tetragonal HgBa2Cu O4+δ . Phys. Rev. Lett. 92, 197005 (2004)
Pintschovius, L. et al. Evidence for dynamic charge stripes in the phonons of optimally doped YBCO. Preprint at http://www.arxiv.org/PS_cache/cond-mat/pdf/0308/0308357.pdf (2003).
Pintschovius, L. & Braden, M. Anomalous dispersion of LO phonons in La1.85Sr0.15CuO4 . Phys. Rev. B 60, R15039 (1999)
Fukuda, T. et al. Doping dependence of softening in the bond-stretching phonon mode of La2-xSrxCuO4 (0 ≤ x ≤ 0.29). Phys. Rev. B 71, 060501(R) (2005)
Reznik, D., Keimer, B., Dogan, F. & Aksay, I. A. q Dependence of self-energy effects of the plane oxygen vibration in YBa2Cu3O7 . Phys. Rev. Lett. 75, 2396–2399 (1995)
Rösch, O. & Gunnarsson, O. Electron-phonon interaction in the t–J model. Phys. Rev. Lett. 92, 146403 (2004)
Ishihara, S. & Nagaosa, N. Interplay of electron-phonon interaction and electron correlation in high-temperature superconductivity. Phys. Rev. B 69, 144520 (2004)
Kaneshita, E., Ichioka, M. & Machida, K. Phonon anomalies due to collective stripe modes in high Tc cuprates. Phys. Rev. Lett. 88, 115501 (2002)
Hiraka, H. et al. Spin fluctuations in the underdoped high-Tc cuprate La1.93Sr0.07CuO4 . Phys. Soc. Jpn 70, 853–858 (2001)
Hinkov, V. et al. Two-dimensional geometry of spin excitations in the high temperature superconductor YBa2Cu3O6+x . Nature 430, 650–654 (2004)
Zhou, X. J. et al. One-dimensional electronic structure and suppression of d-wave node state in La1.28Nd0.6Sr0.12CuO4 . Science 286, 268–272 (1999)
G.D.G. and J.M.T. are supported by the Office of Science, US Department of Energy. K.Y., M.F. and M.S. are supported by grants from the MEXT of Japan. D.R. thanks S. Kivelson for comments on the first version of the manuscript.
Reprints and permissions information is available at npg.nature.com/reprintsandpermissions. The authors declare no competing financial interests.
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