Related papers: Dichotomy in the $T$-linear resistivity in hole-do…
The contribution of superconducting fluctuations to the conductivity, or paraconductivity is studied in the underdoped regime of $La_{2-x}Sr_xCuO_4$ cuprates. A perpendicular magnetic field up to 50 T is applied to suppress the…
One of the most widely discussed features of the cuprate high Tc superconductors is the presence of a pseudogap in the normal state. Recent transport and specific heat measurements have revealed an abrupt transition at the pseudogap…
The influence of the hydrostatic pressure P up to 0.95 GPa on the excess conductivity and the pseudogap {\Delta}*(T) in optimally doped YBCO single crystals (T_c = 91.1K at ambient pressure) is investigated by electrical resistivity…
Although it is generally accepted that superconductivity (SC) is unconventional in the high- transition temperature copper oxides (high-Tc cuprates), the relative importance of phenomena such as spin and charge (stripe) order, SC…
I present a selection of experimental results on metallic cuprates, both above the superconducting transition temperature $T_c$ (often called the strange metal state) and in the superconducting state. It highlights this still poorly…
The thermal conductivity $\kappa$ of the cuprate superconductor La$_{1.6-x}$Nd$_{0.4}$Sr$_x$CuO$_4$ was measured down to 50 mK in seven crystals with doping from $p=0.12$ to $p=0.24$, both in the superconducting state and in the magnetic…
In doped SrTiO$_{3}$ superconductivity persists down to an exceptionally low concentration of mobile electrons. This restricts the relevant energy window and possible pairing scenarios. We present a study of quantum oscillations and…
La$_{1.67}$Sr$_{0.33}$CuO$_4$ is not a superconductor and its resistivity follows a purely T$^2$ temperature dependence at very low temperatures. La$_{1.71}$Sr$_{0.29}$CuO$_4$, on the other hand, has a superconducting ground state together…
We report that it is possible to obtain a series of high-quality crystals of La-doped Bi-2201, of which the transport properties have been believed to be "dirtier" than those of other cuprates. In our crystals, the normal-state transport…
We have studied the density of states of the normal state of the electron-doped superconductor Pr$_{2-x}$Ce$_x$CuO$_4$ at low temperatures and in magnetic fields up to 31 Tesla using point contact spectroscopy on single crystals. Our data…
We propose a theoretical description of the superconducting state of under- to overdoped cuprates, based on the short coherence length of these materials and the associated strong pairing fluctuations. The calculated $T_c$ and the zero…
We carried out a comparative study of the in-plane resistivity and optical spectrum of doped BaFe2As2 and investigated the doping evolution of the charge dynamics. For BaFe2As2, charge dynamics is incoherent at high temperatures. Electron…
Temperature-dependent inter-plane resistivity, $\rho _c(T)$, was measured in hole-doped iron-arsenide superconductor (Ba$_{1-x}$K$_x$)Fe$_2$As$_2$ over a doping range from parent compound to optimal doping $T_c\approx 38~K$, $0\leq x \leq…
We reconsider transport experiments in strongly anisotropic superconducting cuprates and we find that universal Aslamazov-Larkin (AL) paraconductivity in two dimensions is surprisingly robust even in the underdoped regime below the…
To elucidate how the temperature dependence of the resistivity anisotropy of the cuprate superconductors changes with hole doping, both the in-plane and the out-of-plane resistivities (\rho_{ab} and \rho_{c}) are measured in a series of…
The thermopower S of the high-Tc superconductor La(1.6-x)Nd(0.4)Sr(x)CuO(4) was measured as a function of temperature T near its pseudogap critical point, the critical hole doping p* where the pseudogap temperature T* goes to zero. Just…
We express the superconducting gap, $\Delta(T)$, in terms of thermodynamic functions in both $s$- and d-wave symmetries. Applying to Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ and Y$_{0.8}$Ca$_{0.2}$Ba$_2$Cu$_3$O$_{7-\delta}$ we find that for all…
Cuprate superconductors have long been known to exhibit an energy gap that persists high above the superconducting transition temperature ($T_c$). Debate has continued now for decades as to whether it is a precursor superconducting gap or a…
We demonstrate that the zero-temperature superconducting phase diagram of underdoped cuprates can be quantitatively understood in the strong binding limit, using only the experimental spectral function of the "normal" pseudo-gap phase…
Hole doping of superconducting cuprates generates lattice defects of O atoms. At and beyond closing of the pseudogap, p =< p*, they form a highly symmetric superlattice. Umklapp processes involving reciprocal lattice vectors associated with…