Berlin 2005 – scientific programme

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TT: Tiefe Temperaturen

TT 5: Superconductivity - Mechanisms, Phase Diagram, Competing Order

TT 5.3: Talk

Friday, March 4, 2005, 18:30–18:45, TU H104

Excitation spectrum of d-wave Fermi surface deformation — •Hiroyuki Yamase — Max-Planck-Institute for Solid State Research, Heisenbergstrasse 1, D-70569, Stuttgart, Germany

The d-wave Fermi surface deformation (dFSD) is one of possible orders competing with the d-wave singlet pairing, and is generated by forward scattering processes of electrons. We report dynamical properties of the dFSD and calculate its correlation functions within the random phase approximation. In the normal state, the excitation spectrum shows a low energy peak, which smoothly connects to critical fluctuations of the dFSD at lower temperature. The competition with the d-wave pairing, however, blocks the critical fluctuations. The whole spectral weight is transferred to high energy where a pronounced peak appears in the d-wave pairing state. This peak is an overdamped collective mode of the dFSD and can grow to become a resonance mode at moderate finite wavevectors.