Abstract
Interest in vortex matter has risen considerably since the discovery of the high-temperature superconductors, which exhibit magnetic vortex states that are especially rich and complex1. The global behaviour of magnetic vortices in nearly perfect crystals—such as melting of the vortex lattice2,3,4,5—has been much studied, but of more technological relevance is the influence on the vortex states of the various structural defects present in most practical superconductors. An important example of such a defect is the twin boundary present in twinned orthorhombic crystals of YBa2Cu3O7−δ (YBCO). Studies of such samples using magnetic-field-sensitive probes6,7,8,9 have suggested that the twin boundary plays an important role in pinning the vortices and so enhancing the currents that YBCO can support while remaining superconducting. But the low spatial resolution of these techniques does not permit these effects to be studied at the scale of the vortices or boundaries themselves. Scanning tunnelling spectroscopy offers a means of circumventing these problems of resolution10,11,12, as it directly probes the superconducting order parameter at nanometre length scales. Here we use this technique to investigate the importance of twin boundaries in YBCO. In particular, we observe an unexpectedly large pinning strength for perpendicular vortex flux across the boundary, which implies that the critical current that can be supported along the boundary approaches the theoretical ‘depairing’ limit.
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References
Blatter, G., Feigel'man, M. V. & Vinokur, V. M. Vortices in high-temperature superconductors. Rev. Mod. Phys. 66, 1125–1388 (1994).
Cubitt, R. et al. Direct observation of magnetic flux lattice melting and decomposition in the high T csuperconductor Bi2.15Sr1.95CaCu2O8+x. Nature 365, 407–411 (1993).
Schilling, A. et al. Calorimetric measurement of the latent heat of vortex-lattice melting in untwinned YBa2Cu3O7−δ. Nature 382, 791–793 (1996).
Roulin, M., Junod, A. & Walker, E. Flux line lattice melting transition in YBa2Cu3O6.94observed in specific heat experiments. Science 273, 1210–1212 (1996).
Junod, A. et al. Specific heat peaks observed at to 16T on the melting line of the vortex lattice in YBa2Cu3O7. Physica C 275, 245–258 (1997).
Gammel, P. L. et al. Observation of a novel cortex structure given by magnetic interactions near a sawtooth twin boundary in YBa2Cu3O7−δ. Phys. Rev. Lett. 69, 3808–3811 (1992).
Duran, C. A. et al. Real-time imaging of the magnetic flux distribution in superconducting YBa2Cu3O7−δ. Nature 357, 474–477 (1992).
Vlasko-Vlasov, V. K. et al. Study of the influence of individual twin boundaries on the magnetic flux penetration in YBa2Cu3O7−δ. Phys. Rev. Lett. 72, 3246–3249 (1994).
Welp, U. et al. Magneto-optical study of twin boundary pinning in YBa2Cu3O7−δ. Physica C 235–240;, 241–244 (1994).
Hess, H. F., Robinson, R. B., Dynes, R. C., Valles, J. M. Jr. & Waszczak, J. V. Scanning-tunneling-microscope observation of the Abrikosov flux lattice and the density of states near and inside a fluxoid. Phys. Rev. Lett. 62, 214–217 (1989).
Renner, Ch., Kent, A. D., Niedermann, Ph., Fischer, Ø & Oslash;. & Lévy, F. Scanning tunneling spectroscopy of a vortex core from the clean to the dirty limit. Phys. Rev. Lett. 67, 1650–1653 (1991).
Maggio-Aprile, I., Renner, Ch., Erb, A., Walker, E. & Fischer, Ø & Oslash;. Direct vortex lattice imaging and tunneling spectroscopy of flux lines on YBa2Cu3O7−δ. Phys. Rev. Lett. 75, 2754–2757 (1995).
Erb, A., Walker, E. & Flükiger, R. BaZrO3: The solution for the crucible corrosion problem during the single crystal growth of high-T csuperconductors REBa2Cu3O7−δ; RE = Y, Pr. Physica C 245, 245–251 (1995).
Renner, Ch., Niedermann, Ph., Kent, A. D. & Fischer, Ø & Oslash;. Aversatile low-temperature scanning tunneling microscope. J. Vac. Sci. Technol. A 8, 330–332 (1990).
Kent, A. D., Renner, Ch., Niedermann, Ph. & Fischer, Ø & Oslash;. Alow-temperature scanning tunneling microscope with in-situ sample cleaving. Ultramicroscopy 42–44, 1631–1637 (1992).
Crabtree, G. W. et al. Time-dependent Ginzburg-Landau simulations of vortex guidance by twin boundaries. Physica C 263, 401–408 (1996).
Keimer, B. et al. Vortex lattice symmetry and electronic structure in YBa2Cu3O7. Phys. Rev. Lett. 73, 3459–3462 (1994).
Ternovskii, F. F. & Shekhata, L. N. Structure of the mixed state near the boundary of a semi-finite type II superconductor of the second kind. Sov. Phys.-JETP 35, 1202–1208 (1972).
Acknowledgements
We thank R. Flükiger, A. Takagi, J.-G. Bosch, M.G. Karkut and C.H. Ahn for experimental assistance and critical comments about the manuscript. This work was supported by the Swiss National Science Foundation.
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Maggio-Aprile, I., Renner, C., Erb, A. et al. Critical currents approaching the depairing limit at a twin boundary in YBa2Cu3O7−δ. Nature 390, 487–490 (1997). https://doi.org/10.1038/37312
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DOI: https://doi.org/10.1038/37312
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