Phase diagram and thermal expansion measurements on the system URu2-xFexSi2.

Thermal expansion, electrical resistivity, magnetization, and specific heat measurements were performed on URuFeSi single crystals for various values of Fe concentration x in both the hidden-order (HO) and large-moment antiferromagnetic (LMAFM) regions of the phase diagram. Our results show that the paramagnetic (PM) to HO and LMAFM phase transitions are manifested differently in the thermal expansion coefficient. The uniaxial pressure derivatives of the HO/LMAFM transition temperature T change dramatically when crossing from the HO to the LMAFM phase.

Two-component dynamics of the order parameter of high temperature Bi2Sr2CaCu2O8+delta superconductors revealed by time-resolved Raman scattering.

We study the dynamics of the superconducting order parameter in the high-Tc cuprate Bi2Sr2CaCu2O8+delta by employing a novel time-resolved pump-probe Raman experiment. We find two different coupling mechanisms that contribute equally to the pair-breaking peak. One coupling sets in very fast at 2 ps and relaxes slowly, while the other one is delayed and sets in roughly at 5 ps and relaxes fast.

Gaplike excitations in the superconducting state of Bi2Sr2CaCu2O8 studied by resonant Raman scattering.

We report on the response of the electronic continuum from inelastic light-scattering experiments over an extended energy range between 1.970 and 4.504 eV in the superconducting state of Bi2Sr2CaCu2O8.