Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.
DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.
We have irradiated by thermal neutrons single crystals of the Bi-2212 high T-c superconductor. The irradiated samples are insulators, but they regain high T-c superconductivity after an annealing in He at 450-550 degrees C. Depending on irradiation doses a ...
We have studied the influence of Co and Ni doping on the electronic band structure and the transport properties of high-temperature superconductors. The doping has dramatic effects on both the normal and the superconducting state. Upon doping the residual ...
Using angle-resolved photoemission, we report the first observation of an incomplete charge-density-wave (CDW) gap opening for the quasi-two-dimensional material Mo4O11. Our data indicate that the gap opening occurs over a range of 0.5 (A)ngstrom(-1) in th ...
We show that the average lattice disorder in YBa2Cu3O6.9 films grown by ion-beam sputtering is homogeneous and can be quantified by introducing the lattice coherence length rc that is extracted from the width of X-ray diffraction rocking curves. The superc ...
We performed angle-resolved photoemission experiments on overdoped single crystal Bi2Sr2CaCu2O8+x samples with Tc values as low as 55K and very narrow transitions as measured by AC susceptibility. The photoemission data indicate the presence of a ''shadow' ...
Doping Bi2Sr2Ca1Cu2O8+y with Co causes a superconductor-insulator transition. We study correlations between changes in the electrical resistivity rho(ab)(T) and the electronic bandstructure using identical single crystalline samples. For undoped samples th ...
We report on striking sensitivity of the superconducting properties of ion-beam sputtered YBa2Cu3O6.9 films to the lattice disorder (induced by varying growth temperatures). Tc decreases with increasing disorder, while the width of the resistive transition ...
Angle-resolved photoemission data taken on some Bi2Sr2CaCu2O8+y single crystals exhibit the formation of a superconducting gap in the absence of a quasiparticle normal state band. We observe the opening of the superconducting gap in the same regions of the ...
We discuss the striking changes of the superconducting properties of YBa2Cu3O6.9 films to the homogeneous lattice disorder, induced by varying growth temperatures: Tc decreases with increasing disorder, while the width of the resistive transition and the n ...
The authors studied the electric structure of two high-temperature superconductors, with particular emphasis on photoemission resonance effects and on collective excitation phenomena. The photoemission resonances simplified the identification of valence sp ...
