S. V. Dordevic

A UNIVERSAL SCALING RELATION IN HIGH-TEMPERATURE SUPERCONDUCTORS

Since the discovery of superconductivity at elevated temperatures in the copper oxide materials there has been a considerable effort to find universal trends and correlations amongst physical quantities, as a clue to the origin of the superconductivity. One of the earliest patterns that emerged was the linear scaling of the superfluid density (ρs) with the superconducting transition temperature (Tc), which marks the onset of phase coherence. This is referred to as the Uemura relation, and it works reasonably well for the underdoped materials. It does not, however, describe optimally doped (where Tc is a maximum) or overdoped materials. Similarly, an attempt to scale the superfluid density with the d.c. conductivity (σdc) was only partially successful. Here we report a simple scaling relation (ρs∝σdcTc, with σdc measured at approximately Tc) that holds for all tested high-Tc materials. It holds regardless of doping level, nature of dopant (electrons versus holes), crystal structure and type of disorder, and direction (parallel or perpendicular to the copper–oxygen planes).

Infrared probe of the anomalous magnetotransport of highly oriented pyrolytic graphite in the extreme quantum limit

We present a systematic investigation of the magnetoreflectance R ,B of highly oriented pyrolytic graphite in magnetic field B up to 18 T. From these measurements, we report the determination of lifetimes associated with the lowest Landau levels in the quantum limit. We find a linear field dependence for inverse lifetime 1 /B of the lowest Landau levels, which is consistent with the hypothesis of a three-dimensional 3D to 1D crossover in an anisotropic 3D metal in the quantum limit. This enigmatic result uncovers the origin of the anomalous linear in-plane magnetoresistance observed both in bulk graphite and recently in mesoscopic graphite samples.

Sum rules and energy scales in the high-temperature superconductorYBa2Cu3O6+x

The Ferrell-Glover-Tinkham (FGT) sum rule has been applied to the temperature dependence of the in-plane optical conductivity of optimally doped

Extracting the electron-boson spectral function a 2 FÑvÖ from infrared and photoemission data using inverse theory

{\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{6.95}

Signatures of charge inhomogeneities in the infrared spectra of topological insulators Bi2Se3, Bi2Te3 and Sb2Te3

and underdoped

Electrodynamics of correlated electron matter

{\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{6.60}.

Optical signatures of momentum-dependent hybridization of the local moments and conduction electrons in Kondo lattices

Within the accuracy of the experiment, the sum rule is obeyed in both materials. However, the energy scale

Optical and thermodynamic properties of the high-temperature superconductor HgBa 2 CuO 4+δ

{\ensuremath{\omega}}_{c}

Coherence, incoherence, and scaling along the c axis of YBa2Cu3O6+x

required to recover the full strength of the superfluid

Signatures of electron-boson coupling in the half-metallic ferromagnet Mn 5 Ge 3 : Study of electron self-energy Σ ( ω ) obtained from infrared spectroscopy

{\ensuremath{\rho}}_{s}