N. Bontemps

Infrared properties of electron-doped cuprates: Tracking normal-state gaps and quantum critical behavior in Pr2 − xCexCuO4

We report the temperature dependence of the infrared-visible conductivity of Pr2 − xCexCuO4 thin films. When varying the doping from a non-superconducting film (x = 0.11) to a superconducting overdoped film (x = 0.17), we observe, up to optimal doping (x = 0.15), a partial gap opening. The magnitude of this gap extrapolates to zero for x ~ 0.17. A model combining a spin density wave gap and a frequency- and temperature-dependent self-energy reproduces our data reasonably well, suggesting the coexistence of magnetism and superconductivity in this material and the existence of a quantum critical point at this Ce concentration.

Two-Fermi-surface superconducting state and a nodal d-wave energy gap of the electron-doped Sm1.85Ce0.15CuO(4-δ) cuprate superconductor.

We report on laser-excited angle-resolved photoemission spectroscopy in the electron-doped cuprate Sm1.85Ce0.15CuO(4-δ). The data show the existence of a nodal hole-pocket Fermi surface both in the normal and superconducting states. We prove that its origin is long-range antiferromagnetism by an analysis of the coherence factors in the main and folded bands. This coexistence of long-range antiferrmagnetism and superconductivity implies that electron-doped cuprates are two-Fermi-surface superconductors. The measured superconducting gap in the nodal hole pocket is compatible with a d-wave symmetry.

Infrared signature of the superconducting state in Pr2−xCexCuO4

We measured the far infrared reflectivity of two superconducting

Temperature dependence of the spectral weight in p- and n-type cuprates: A study of normal state partial gaps and electronic kinetic energy

{\mathrm{Pr}}_{2\ensuremath{-}x}{\mathrm{Ce}}_{x}\mathrm{Cu}{\mathrm{O}}_{4}

Optical spectroscopy as a probe of gaps and kinetic electronic energy in p- and n-type cuprates

films above and below

Far-infrared transmission of YBa2Cu3O7−δ thin films

{T}_{c}

Magnetisation measurements and irreversibility lines in (PrBa2Cu3−xGaxO7)M/(YBa2Cu3O7)N superlattices

. The reflectivity in the superconducting state increases and the optical conductivity drops at low energies, in agreement with the opening of a (possibly) anisotropic superconducting gap. The maximum energy of the gap scales roughly with

Optical Properties of (Pr,Ce)2CuO4

{T}_{c}

Sum Rules and Energy Scales in BiSrCaCuO

as

Penetration depth from far-infrared transmission in YBa2Cu3O7 thin films

2{\ensuremath{\Delta}}_{\mathrm{max}}∕{k}_{B}{T}_{c}\ensuremath{\approx}4.7