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The spin resonance and high frequency optical properties of the cuprates
We argue that recently observed superconductivity-induced blue shift of the
plasma frequency in is
related to the change in the integrated dynamical structure factor associated
with the development of the spin resonance below . We show that the
magnitude of is consistent with the small integrated
spectral weight of the resonance, and its temperature dependences closely
follow that of the spin resonance peak.Comment: 5 pages, 3 figure
DHCR7 mutations linked to higher vitamin D status allowed early human migration to Northern latitudes
PMCID: PMC3708787This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Dispersion Anomalies in Cuprate Superconductors
We argue that the shape of the dispersion along the nodal and antinodal
directions in the cuprates can be understood as a consequence of the
interaction of the electrons with collective spin excitations. In the normal
state, the dispersion displays a crossover at an energy where the decay into
spin fluctuations becomes relevant. In the superconducting state, the antinodal
dispersion is strongly affected by the spin resonance and displays an S-shape
whose magnitude scales with the resonance intensity. For nodal fermions,
relevant spin excitations do not have resonance behavior, rather they are
better characterized as a gapped continuum. As a consequence, the S-shape
becomes a kink, and superconductivity does not affect the dispersion as
strongly. Finally, we note that optical phonons typically lead to a temperature
independent S-shape, in disagreement with the observed dispersion.Comment: 12 pages, 7 eps figure
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