Dresden 2006 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 30: Superconductivity: Twenty Years High-Tc Cuprates - Recent Progress
TT 30.11: Vortrag
Donnerstag, 30. März 2006, 16:45–17:00, HSZ 02
Dopant-modulated pair interaction in cuprate superconductors — •Tamara Nunner1, Brian Andersen2, Ashot Melikyan2, and Peter Hirschfeld2 — 1Institut fuer theoretische Physik, FU Berlin, Arnimallee 14, 14195 Berlin — 2Department of Physics, University of Florida, Gainesville, FL 32611 (USA)
High-resolution STM experiments on superconducting BSCCO-2212 have revealed the existence of nanoscale inhomogeneities in the electronic structure at biases near the superconducting energy gap. Very recently, a strong correlation between this nanoscale electronic disorder and the locations of the oxygen dopant atoms has been identified by McElroy et al. [1]. We suggest that the primary effect of the oxygen dopant atoms is to modulate the pair interaction locally [2]. Based on single impurity T-matrix and many-impurity Bogoliubov-de Gennes calculations we show that a dopant modulated pair interaction can reproduce most of the correlations observed in recent STM experiments: nanoscale inhomogeneity of the coherence peak position, homogeneity of the local density of states at low bias, low charge disorder, negative correlation between the height of the coherence peaks and the gap magnitude and a positive correlation between the gap magnitude and the locations of the oxygen dopant atoms.
[1] K. McElroy, J. Lee, J. A. Slezak, D.-H. Lee, H. Eisaki, S. Uchida, and J.C. Davis, Science 309, 1048 (2005).
[2] T.S. Nunner, B.M. Andersen, A. Melikyan, and P.J. Hirschfeld, Phys. Rev. Lett. 95, 177003 (2005).