Defect-induced changes in the spectral properties of high-Tc cuprates
Superconductivity in high-T<sub>c</sub> cuprates is particularly sensitive to disorder due to the unconventional d-wave pairing symmetry. We investigated effects of disorder on the spectral properties of Bi<sub>2</sub>Sr<sub>2</sub>CaCu<sub>2</sub>O<sub>8+x</sub> high-T<sub>c</sub> superconductor. We found that already small defect densities suppress the characteristic spectral signature of the superconducting state. The spectral line shape clearly reflects new excitations within the gap, as expected for defect-induced pair breaking. At the lowest defect concentrations the normal state remains unaffected, while increased disorder leads to suppression of the normal quasiparticle peaks
1999
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3
107
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Inst. de Phys. Appliquee, Ecole Polytech. Federale de Lausanne, Switzerland
6642799
REVIEWED