We report resonant electronic Raman scattering in optimally doped single layer HgBa2CuO4+δ (Hg-1201) and trilayer HgBa2Ca2Cu3O8+δ (Hg-1223) single crystals. Analysis of the B1g and B2g channels in the superconducting state of Hg-1201 advocates for a gap having d-wave symmetry. In addition a resonant study B1g pair-breaking peak and the A1g peak suggests that the A1g peak is not directly related...

Using angle-resolved photoemission spectroscopy, we report on the direct observation of the energy gap in 2H-NbSe2 caused by the charge-density waves (CDW). The gap opens in the regions of the momentum space connected by the CDW vectors, which implies a nesting mechanism of CDW formation. In remarkable analogy with the pseudogap in cuprates, the detected energy gap also exists in the normal sta...

A mixed mean-field/BCS phase with an energy gap at high T c Abstract We construct a pair potential which in a scaling limit leads to a Hamiltonian that generates co-existing mean-field and superconducting phases. Depending on the relative values of the coupling constants, the superconducting phase may exist at arbitrarily high temperatures. ⋆ Work supported in part by " Fonds zur Förderung der ...

Neutron resonance spin-echo spectroscopy was used to monitor the temperature evolution of the linewidths of transverse acoustic phonons in lead across the superconducting transition temperature over an extended range of the Brillouin zone. For phonons with energies below the superconducting energy gap, a linewidth reduction of maximum amplitude was observed below . The electron-phonon contribut...

We have performed measurements of the surface impedance in the normal and superconducting states of the title compounds in the millimeter wave-frequency range (1-3 cm-1), and have evaluated the complex conductivity for different crystallographic orientations. Above the transition temperature, the materials behave like metals with a scattering rate of approximately 20 cm -1. In the superconducti...

2014 The conduction band distortion and LO phonon energy of GaAs, the transition temperature, the energy gap and the phonon energies in superconducting lead film, have been measured at pressures up to 30 kbar by electron tunnelling through Schottky barriers. LE JOURNAL DE PHYSIQUE LETTRES TOME 39, 15 NOVEMBRE 1978,

The discovery of high-temperature superconductivity in Fe-based compounds triggered numerous investigations on the interplay between superconductivity and magnetism, and on the enhancement of transition temperatures through interface effects. It is widely believed that the emergence of optimal superconductivity is intimately linked to the suppression of long-range antiferromagnetic (AFM) order,...

Inelastic neutron scattering was used to study the wave vector- and frequency-dependent magnetic fluctuations in single crystals of superconducting YBa2Cu3O6+x. The spectra contain several important features, including a gap in the superconducting state, a pseudogap in the normal state, and the much-discussed resonance peak. The appearance of the pseudogap determined from transport and nuclear ...