Regensburg 2004 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 9: Supraleitung: Eigenschaften, elektronische Struktur, Ordnungsparameter
TT 9.1: Hauptvortrag
Dienstag, 9. März 2004, 09:30–10:00, H20
Wavefunction Imaging Studies of Cuprate Superconductivity — •Séamus Davis1, K. McElroy1, E. W. Hudson2, J. E. Hoffman3, D.-H. Lee3, H. Eisaki4, and S. Uchida5 — 1Department of Physics, LASSP, Cornell University, Ithaca, NY — 2MIT — 3UC Berkeley — 4AIST-Tsukuba — 5Tokyo University
High temperature superconductivity in the cuprates emerges when the localized electrons of a Mott-insulator become itinerant due to carrier-doping. Since cuprate superconductivity develops from atomically localized electrons and exhibits nanoscale disorder, simultaneous information on electronic structure in both the real-space and momentum-space is required. I will describe a combination of novel scanning tunneling microscopy (STM) techniques which achieves these apparently contradictory aims.
The first technique, atomic-resolution spectroscopic mapping, allows imaging of interactions between quasiparticle wavefunctions and the real-space environment at the atomic-scale.
A second technique, Fourier-transform scanning tunneling spectroscopy (FT-STS), is used to study interference patterns of the delocalized wavelike electronic states. For optimally doped samples, analysis of these patterns as due to quasiparticle interference , yields the Fermi surface and the d-wave superconducting energy gap, in excellent agreement with ARPES.
Finally I will describe FTSTS experiments designed to detect and identify the electronic ground state in other regions of the cuprate phase diagram including studies of the vortex core and of strongly underdoped samples.