Abstract
Crucial to the successful development of a theoretical model for high-temperature superconductivity is knowledge of the symmetry of the order parameter (or wavefunction) that describes the pairing of electrons in the superconducting state. Several experimental studies1–8provide convincing evidence for an anisotropic order parameter, consistent with a symmetry. But none of these earlier experiments could rule out unambiguously an additional contribution from isotropic s-wave pairing; these experiments either involved superconductors with an orthorhombic crystal structure (for which a mixed s + d state is becoming increasingly recognized as a likely consequence9,10), or their interpretation required detailed modelling of the uncertain effects of disorder and defects. Here we report the results of an experiment designed to circumvent these difficulties: the material studied is the single-layer tetragonal superconductor Tl2Ba2CuO6+δ, and the experimental configuration is such that the interpretation of the results relies solely on symmetry considerations. Our results indicate that this material has pure pairing symmetry, so providing a starting point for understanding the more complex mixed s + d state that appears to characterize other high-temperature superconductors.
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References
Wollman, D. A., van Harlingen, D. J., Lee, W. C., Ginsberg, D. M. & Leggett, A. J. Experimental determination of the superconducting pairing state in YBCO from the phase coherence of YBCO-PB DC SQUIDs. Phys. Rev. Lett. 71, 2134–2137 (1993).
Brawner, D. A. & Ott, H. R. Evidence for an unconventional superconducting order parameter in YBa2Cu3O6.9 . Phys. Rev. B 50, 6530–6533 (1994).
Tsuei, C. C. et al. Pairing symmetry and flux quantization in a tricrystal superconducting ring of YBa2Cu3O7-δ . Phys. Rev. Lett. 73, 593–596 (1994).
Kirtley, J. R. et al. Symmetry of the order parameter in the high-Tc superconductor YBa2Cu3O7-δ . Nature 373, 225–228 (1995).
Wollman, D. A., van Harlingen, D. J., Giapintzakis, J. & Ginsberg, D. M. Evidence for d x 2 - y 2 pairing from the magnetic field modulation of YBa2Cu3O7-Pb Josephson junctions. Phys. Rev. Lett. 74, 797–800 (1995).
Miller, J. H. Jr et al. Use of tricrystal junctions to probe the pairing state symmetry of YBa2Cu3O7-δ . Phys. Rev. Lett. 74, 2347–2350 (1995).
Mathai, A. et al. Experimental proof of a time reversal invariant order parameter with a π shift in YBa2Cu3O7-δ . Phys. Rev. Lett. 74, 4523–4526 (1995).
Tsuei, C. C. et al. Half-integer flux quantum effect and pairing symmetry in high-Tc tetragonal Tl2Ba2CuO6+δ films. Science 271, 329–332 (1996).
Walker, M. B. & Luettmer-Strathmann, J. Josephson tunneling in high-Tc superconductors. Phys. Rev. B 54, 598–601 (1996).
Sun, A. G., Gajewski, D. A., Maple, M. B. & Dynes, R. C. Observation of pair tunneling between a high-Tc suprate YBa2Cu3O7-δ and a conventional superconductor (Pb). Phys. Rev. Lett. 72, 2267–2270 (1994).
Sigrist, M. & Rice, T. M. Paramagnetic effects in high-Tc superconductors—a hint for d-wave superconductivity. J. Phys. Soc. Jpn 61, 4283–4286 (1992).
Annett, J. F., Goldenfeld, N. & Leggett, A. J. Constrains on the pairing state of cuprate superconductors . J. Low Temp. Phys. 105, 473–482 (1996).
Scalapino, D. J. The case for d x 2 - y 2 pairing in the cuprate superconductors. Phys. Rep. 250, 329–365 (1995).
Li, Q. P., Koltenbach, B. E. C. & Joynt, R. Mixed s and d wave superconductivity in high Tc systems. Phys. Rev. B 48, 437–455 (1993).
Beal-Monod, M. T. & Maki, K. Impurity scattering in s + dwave superconductivity. Europhys. Lett. 33, 309–313 (1996).
Ferrell, R. A. & Prange, R. E. Self-field limiting of Josephson tunneling of superconducting electron pairs. Phys. Rev. Lett. 10, 479–481 (1963).
Ferell, R. A. in High Temperature Superconductivity (ed. Lynn, J. W.) 60–83 (Springer, New York, 1990).
Wang, C. A. et al. Superconducting epitaxial T12Ba2 CuO6+δ thin films on SrTiO3 with tetragonal lattice and continuously adjustable critical temperature. Physica C 262, 98–102 (1996).
Ren, Z. F., Wang, J. H. & Miller, D. J. The structural symmetry of epitaxial Tl2Ba2CuO6+δ thin films. Appl. Phys. Lett. 69, 1798–1800 (1996).
Kirtley, J. R. et al. High-resolution scanning SQUID microscope. Appl. Phys. Lett. 66, 1138–1140 (1995).
Tsuei, C. C. et al. Flux quantization in tricrystal cuprate rings. A new probe of pairing symmetry. J. Phys. Chem. Solids 56, 1787–1795 (1995).
Kirtley, J. R. et al. Direct imaging of integer and half-integer Josephson vortices in high-Tc grain boundaries. Phys. Rev. Lett. 76, 1336–1339 (1996).
Shen, Z.-X. et al. Anomalously large gap anisotropy in the a-b plane of Bi2Sr2CaCu2CuO6+δ . Phys. Rev. Lett. 70, 1553–1556 (1993).
Ding, H. et al. Angle resolved photoemission spectroscopy study of the superconducting gap in Bi2Sr2CaCu2CuO6+δ . Phys. Rev. B 54, 9678–9681 (1996).
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Tsuei, C., Kirtley , J., Ren, Z. et al. Pure order-parameter symmetry in the tetragonal superconductor TI2Ba2CuO6+δ. Nature 387, 481–483 (1997). https://doi.org/10.1038/387481a0
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DOI: https://doi.org/10.1038/387481a0
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