The electronic structure of the high-Tc superconductor Tl2Ba2CuO 6+δ is studied by ARPES. For a very overdoped Tc = 30 K sample, the Fermi surface consists of a single large hole pocket centered at (π,π) and is approaching a topological transition. Although a superconducting gap with d x 2 −y 2 symmetry is tentatively identified, the quasiparticle evolution with momentum and binding energy exhibits a marked departure from the behavior observed in under and optimally doped cuprates. The relevance of these findings to scattering, many-body, and quantum-critical phenomena is discussed.

We apply the new-generation ARPES methodology to the most widely studied cuprate superconductor YBa2Cu3O6+x. Considering the nodal direction, we found noticeable renormalization effects known as "kinks" both in the quasiparticle dispersion and scattering rate, the bilayer splitting and evidence for strong interband scattering -all the characteristic features of the nodal quasiparticles detected earlier in Bi2Sr2CaCu2O 8+δ . The typical energy scale and the doping dependence of the "kinks" clearly point to their intimate relation with the spin-1 resonance seen in the neutron scattering experiments. Our findings strongly suggest a universality of the electron dynamics in the bilayer superconducting cuprates and a dominating role of the spin-fluctuations in the formation of the quasiparticles along the nodal direction.PACS numbers: 74.25.Jb, 74.72.Bk, The presence of similar CuO planes in all hightemperature superconducting (HTSC) cuprates provides a key to understand their puzzling generic phase diagram [1]. On the other hand, the sensitivity of the maximal transition temperatures (T c ) to the rest of the lattice implies that one should study the cuprates as a class of materials aiming to gain the knowledge of how to drive T c . Due to different purity of the samples, their mechanical properties, surface quality, size of the available single crystals etc., a single experimental technique often provides information only about a few members of the large cuprate family. A known example in HTSC research is the trio of the spectroscopic techniques which can be considered as complementary to each other: scanning tunneling spectroscopy [2], inelastic neutron scattering (INS) [3] and angle-resolved photoemission (ARPES) [4]. The first one prefers to deal with Bi 2 Sr 2 CaCu 2 O 8+δ (BSCCO) and fails to study La 2−x Sr x CuO 4 (LSCO) whereas the second one is dominantly applied to YBa 2 Cu 3 O 6+x (YBCO) and LSCO. ARPES has been successfully applied to many holedoped cuprates. Though a hallmark of the modern ARPES is the sensitivity to the many-body effects and up to now only BSCCO and to a lesser degree LSCO turned out to be suitable targets for such studies. Investigations of YBCO by means of photoemission, despite a rich history [5], have been virtually stopped on the verge of the new millennium. In the last (to the best of our knowledge) report [6] the authors do find a single many-body related feature, renown "peak-dip-hump" structure, but leave open some fundamental questions, like the origin of the surface state and the presence of the bilayer splitting (BS). Thus, even the underlying band structure of YBCO, a basic prerequisite to study many-body interactions by ARPES, remains unclear [4].In this Letter we extend the power of the newgeneration ARPES to YBCO cuprates. Our first objective is the nodal direction which is known to be free of the influence of the surface state [5,6]. We find not only a clear indication for the existence of the bilayer splitting but also other typical characteristics of the nodal quasip...

We studied the neutral electronic excitations of NiO localized at the Ni sites by measuring the resonant inelastic x-ray scattering (RIXS) spectra at the Ni M2,3 edges. The good energy resolution allows an unambiguous identification of several spectral features due to excitations. The dependence of the RIXS spectra on the excitation energy gives evidence of local spin flip and yields a value of 125 +/- 15 meV for the antiferromagnetic exchange interaction. Accurate crystal field parameters are also obtained.

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The perfomance of hematite and Ti-substituted hematite nanorods as photoanodes for solar water splitting was quantitavely evaluated from photoelectrochemical point of view. The nanostructure, morphology and chemical / electronic structure...