Condensed-Matter Physics & Materials Science Seminar

A notable role in understanding of microscopic electronic properties of
high temperature superconductors (HTSC) belongs to angle resolved
photoemission spectroscopy (ARPES). This technique supplies a direct
window into reciprocal space of solids: the momentum-energy space where
quasiparticles (the electrons dressed in clouds of interactions) dwell.
Any interaction in the electronic system, e.g. superconducting pairing,
leads to modification of the quasi-particle spectrum--to redistribution of
the spectral weight over the momentum-energy space probed by ARPES. A
continued development of the technique had an effect that the picture seen
through the ARPES window became clearer and sharper until the complexity
of the electronic band structure of the cuprates had been resolved. Now,
in an optimal for superconductivity doping range, the cuprates much
resemble a normal metal with well predicted electronic structure, though
with rather strong electron-electron interaction. This principal
disentanglement of the complex physics from complex structure reduced the
mystery of HTSC to a tangible problem of interaction responsible for
quasi-particle formation. I will present a short overview of resent ARPES
results, which, we believe, denote a way to resolve the HTSC puzzle.