Temporal correlations of superconductivity above the transition temperature in La 2−x Sr x CuO 4 probed by terahertz spectroscopy

Above the superconducting temperature for a given material, correlations between pairs of electrons are already present. Many experiments indicate that such correlations may exist up to 100 K above the transition. However, a temporal probe of the superconducting fluctuations suggests that correlations only exist within a narrow temperature range.