Skip to main content

Thank you for visiting 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.

Electron-spin excitation coupling in an electron-doped copper oxide superconductor


High-temperature (high- Tc) superconductivity in the copper oxides arises from electron or hole doping of their antiferromagnetic (AF) insulating parent compounds. The evolution of the AF phase with doping and its spatial coexistence with superconductivity are governed by the nature of charge and spin correlations, which provides clues to the mechanism of high- Tc superconductivity. Here we use neutron scattering and scanning tunnelling spectroscopy (STS) to study the evolution of the bosonic excitations in electron-doped superconductor Pr0.88LaCe0.12CuO4−δ with different transition temperatures (Tc) obtained through the oxygen annealing process. We find that spin excitations detected by neutron scattering have two distinct modes that evolve with Tc in a remarkably similar fashion to the low-energy electron tunnelling modes detected by STS. These results demonstrate that antiferromagnetism and superconductivity compete locally and coexist spatially on nanometre length scales, and the dominant electron–boson coupling at low energies originates from the electron-spin excitations.

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

Access options

Rent or buy this article

Prices vary by article type



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

Figure 1: Schematic diagram of polarized neutron scattering set-up and polarized neutron scattering data at various temperatures.
Figure 2: Energy dependence of SF and NSF scattering at Q=(1.5,−0.5,0) rlu for the 24 K PLCCO and χ′′(ω) in absolute units for the 21 and 24 K samples.
Figure 3: Comparison of the tunnelling spectra of the 21 and 24 K samples.
Figure 4: Spatial variation of gap and Bosonic modes.


  1. Lee, P. A., Nagaosa, N. & Wen, X. G. Doping a Mott insulator: Physics of high-temperature superconductivity. Rev. Mod. Phys. 78, 17–85 (2006).

    Article  ADS  Google Scholar 

  2. Armitage, N. P., Fournier, P. & Greene, R. L. Progress and perspectives on the electron-doped cuprates. Rev. Mod. Phys. 82, 2421–2487 (2010).

    Article  ADS  Google Scholar 

  3. Capone, M. & Kotliar, G. Competition between d -wave superconductivity and antiferromagnetism in the two-dimensional Hubbard model. Phys. Rev. B 74, 054513 (2006).

    Article  ADS  Google Scholar 

  4. Demler, E., Hanke, W. & Zhang, S-C. SO(5) theory of antiferromagnetism and superconductivity. Rev. Mod. Phys. 76, 909–974 (2004).

    Article  ADS  Google Scholar 

  5. Weber, C., Haule, K. & Kotliar, G. Strength of correlations in electron and hole doped cuprates. Nature Phys. 6, 574–578 (2010).

    Article  ADS  Google Scholar 

  6. 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 

  7. Kivelson, S. A. et al. How to detect fluctuating stripes in the high-temperature superconductors. Rev. Mod. Phys. 75, 1201–1241 (2003).

    Article  ADS  Google Scholar 

  8. Pintschovius, L. & Reichardt, W. in Physical Properties of High Temperature Superconductors, Vol. IV (ed. Ginsberg, D. M.) 295 (World Scientific, 1994).

    Book  Google Scholar 

  9. Fujita, M. et al. Magnetic and superconducting phase diagram of electron-doped Pr1−xLaCexCuO4 . Phys. Rev. B 67, 014514 (2003).

    Article  ADS  Google Scholar 

  10. Kang, H. J. et al. Microscopic annealing process and its impact on superconductivity in T′ -structure electron-doped copper oxides. Nature Mater. 6, 224–229 (2007).

    Article  ADS  Google Scholar 

  11. Li, S. L. Impact of oxygen annealing on the heat capacity and magnetic resonance of superconducting Pr0.88LaCe0.12CuO4−δ . Phys. Rev. B 78, 014520 (2008).

    Article  ADS  Google Scholar 

  12. Dai, P. et al. Electronic inhomogeneity and competing phases in electron-doped superconducting Pr0.88LaCe0.12CuO4−δ . Phys. Rev. B 71, 100502(R) (2005).

    Article  ADS  Google Scholar 

  13. Wilson, S. D. et al. Evolution of low-energy spin dynamics in the electron-doped high-transition temperature superconductor Pr0.88LaCe0.12CuO4−δ . Phys. Rev. B 74, 144514 (2006).

    Article  ADS  Google Scholar 

  14. Wilson, S. D. et al. Resonance in the electron-doped high-transition-temperature superconductor Pr0.88LaCe0.12CuO4−δ . Nature 442, 59–62 (2006).

    Article  ADS  Google Scholar 

  15. Wilson, S. D. et al. High-energy spin excitations in the electron-doped superconductor Pr0.88LaCe0.12CuO4−δ with Tc=21 K. Phys. Rev. Lett 96, 157001 (2006).

    Article  ADS  Google Scholar 

  16. Dagan, Y., Qazilbash, M. M., Hill, C. P., Kulkarni, V. N. & Greene, R. L. Evidence for a quantum phase transition in Pr2−xCexCuO4−δ from transport measurements. Phys. Rev. Lett. 92, 167001 (2004).

    Article  ADS  Google Scholar 

  17. Motoyama, E. M. et al. Spin correlations in the electron-doped high-transition-temperature superconductor Nd2−xCexCuO4 . Nature 445, 186–189 (2007).

    Article  ADS  Google Scholar 

  18. Niestemski, F. C. et al. A distinct bosonic mode in an electron-doped high-transition-temperature superconductor. Nature 450, 1058–1061 (2007).

    Article  ADS  Google Scholar 

  19. Zhao, G. M. Fine structure in the tunneling spectra of electron-doped cuprates: No coupling to the magnetic resonance mode. Phys. Rev. Lett 103, 236403 (2009).

    Article  ADS  Google Scholar 

  20. Bardeen, J., Cooper, L. N. & Schrieffer, J. R. Theory of superconductivity. Phys. Rev. 108, 1175–1204 (1957).

    Article  ADS  MathSciNet  Google Scholar 

  21. McMillan, W. L. & Rowell, J. M. Lead phonon spectrum calculated from superconducting density of states. Phys. Rev. Lett. 14, 108–112 (1965).

    Article  ADS  Google Scholar 

  22. Maier, T. A., Poilblanc, D. & Scalapino, D. J. Dynamics of the pairing interaction in the Hubbard and tJ models of high-temperature superconductors. Phys. Rev. Lett 100, 237001 (2008).

    Article  ADS  Google Scholar 

  23. Moon, R. M., Riste, T. & Koehler, W. C. Polarization analysis of thermal-neutron scattering. Phys. Rev. 181, 920–931 (1969).

    Article  ADS  Google Scholar 

  24. Eschrig, M. The effect of collective spin-1 excitations on electronic spectra in high- Tc superconductors. Adv. Phys. 55, 47–183 (2006).

    Article  ADS  Google Scholar 

  25. Boothroyd, A. T., Doyle, S. M., Paul, D. M. K. & Osborn, R. Crystal-field excitations in Nd2CuO4,Pr2CuO4, and related n -type superconductors. Phys. Rev. B 45, 10075–10086 (1992).

    Article  ADS  Google Scholar 

  26. Kruger, F. et al. Magnetic fluctuations in n -type high- Tc superconductors reveal breakdown of fermiology: Experiments and Fermi-liquid/RPA calculations. Phys. Rev. B 76, 094506 (2007).

    Article  ADS  Google Scholar 

  27. Pasupathy, A. N. et al. Electronic origin of the inhomogeneous pairing interaction in the high-T c superconductor Bi2Sr2CaCu2O8+d . Science 320, 196–201 (2008).

    Article  ADS  Google Scholar 

  28. Alldredge, J. W. et al. Evolution of the electronic excitation spectrum with strongly diminishing hole density in superconducting Bi2Sr2CaCu2O8+δ . Nature Phys. 4, 319–326 (2008).

    Article  Google Scholar 

  29. Lee, J. et al. Interplay of electron–lattice interactions and superconductivity in Bi2Sr2CaCu2O8+δ . Nature 442, 546–550 (2006).

    Article  ADS  Google Scholar 

  30. Stock, C. et al. Central mode and spin confinement near the boundary of the superconducting phase in YBa2Cu3O6.353 (Tc=18 K). Phys. Rev. B 73, 100504(R) (2006).

    Article  ADS  Google Scholar 

Download references


The neutron scattering work at UT/ORNL is supported by the US NSF-OISE-0968226, and by the US DOE, Division of Scientific User Facilities (P.D.). Work at BC is supported by US NSF-CAREER-0645299 (V.M.) and DOE DE-SC0002554 (Z.W.). The single crystal PLCCO growth effort at UT is supported by US DOE BES under Grant No. DE-FG02-05ER46202 (P.D.). Work at IOP is supported by the Chinese Academy of Sciences, the Ministry of Science and Technology of China (973 Project nos. 2010CB833102 and 2010CB923002). J.Z. is supported by a fellowship from Miller Institute of Basic Research in Science at Berkeley.

Author information

Authors and Affiliations



P.D. and V.M. planned the neutron and STM experiments, respectively. J.Z., S.L., P.S., A.H., H.J.K., S.D.W. and P.D. carried out neutron scattering measurements and data analysis. F.C.N., S.K. and V.M. performed STM/STS measurements. The samples were grown by J.Z. and S.L. The paper was written by P.D., V.M. and Z.W. with input from J.Z., S.D.W., and F.C.N. All coauthors provided comments on the paper.

Corresponding authors

Correspondence to Pengcheng Dai or V. Madhavan.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 1942 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Zhao, J., Niestemski, F., Kunwar, S. et al. Electron-spin excitation coupling in an electron-doped copper oxide superconductor. Nature Phys 7, 719–724 (2011).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


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