In: New Journal of Physics, 2009, vol. 11, p. 055050
We present a muon spin rotation (μSR) study of the magnetic and superconducting properties of single crystals of electron-doped BaFe2−xCoxAs₂ with x = 0.08, 0.20 and 0.25 (Tc = 9, 25 and 20 K) and of polycrystalline hole-doped Pr1−xSrxFeAsO with x = 0 and 0.2 (Tc = 15...
|
In: Physical Review Letters, 2008, vol. 101, no. 9, p. 097010
Muon spin rotation experiments were performed on the pnictide high temperature superconductor SmFeAsO1-xFx with x=0.18 and 0.3. We observed an unusual enhancement of slow spin fluctuations in the vicinity of the superconducting transition which suggests that the spin fluctuations contribute to the formation of an unconventional superconducting state. An...
|
In: Nature Materials, 2009, vol. 8, p. 310 - 314
|
In: Physical Review Letters, 2008, vol. 101, no. 9, p. 097011
We present far-infrared ellipsometric measurements of polycrystalline samples of the pnictide superconductor RFeAsO0.82F0.18 (R=Nd and Sm). We find evidence that the electronic properties are strongly anisotropic such that the optical spectra are dominated by the weakly conducting c-axis response similar to the cuprate high-temperature superconductors....
|
In: Physical Review Letters, 2010, vol. 104, p. 156807
With infrared ellipsometry and transport measurements we investigated the electrons at the interface between LaAlO₃ and SrTiO₃. We obtained a sheet carrier concentration of Ns≈5–9×10¹³ cm⁻², an effective mass of m*=3.2±0.4me, and a strongly frequency dependent mobility. The latter are similar as in bulk SrTi1-xNbxO₃ and...
|
In: The European Physical Journal - Special Topics, 2010, vol. 188, no. 1, p. 73-88
With the technique of infrared ellipsometry we performed a detailed study of the temperature- and doping dependence of the c-axis response of a series of YBa₂Cu₃O7−δ single crystals. In particular, we explored the anomalous electronic properties at temperatures above the macroscopic superconducting transition temperature, T c, whose conflicting...
|
In: Physical Review Letters, 2011, vol. 106, no. 4, p. 047006
We show that a multilayer analysis of the infrared c-axis response of RBa₂Cu₃O7-δ (R=Y,Gd,Eu) provides important new information about the anomalous normal-state properties of underdoped cuprate high temperature superconductors. In addition to competing correlations which give rise to a pseudogap that depletes the low-energy electronic states below...
|
In: Nature Materials, 2009, vol. 8, p. 315-319
|
In: Clinical Oral Investigations, 2013, vol. 17, no. 1, p. 167-175
|
In: Physical Review B, 2010, vol. 81, p. 214508
We performed combined infrared reflection and ellipsometry measurements of the in-plane optical response of single crystals of the pnictide high-temperature superconductor BaFe1.87Co0.13As₂ with Tc=24.5 K. Our experimental data provide evidence for multiple superconducting energy gaps and can be well described in terms of three isotropic gaps with...
|
