Superconductivity and the c axis spectral weight of high-T(c) superconductors
The temperature dependence of the c axis spectral weight (frequency integral of the interplane conductivity) of high transition temperature (high-T(c)) superconductors is shown to be a probe of thermal and quantal fluctuations of the phase of the superconducting order parameter. The behavior of underdoped cuprates is shown to be a natural consequence of superconducting pairing without long-ranged phase coherence. Very underdoped cuprates are found to have strong phase fluctuations, even for temperatures much less than the transition temperature.
Ioffe
LB
Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854, USA.
Millis
AJ