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1.
Background
Growth hormone (GH) plays an incompletely understood role in the development of the central nervous system (CNS). In this study, we use transgenic mice expressing a growth hormone antagonist (GHA) to explore the role of GH in regulating postnatal brain, spinal cord and body growth into adulthood. The GHA transgene encodes a protein that inhibits the binding of GH to its receptor, specifically antagonizing the trophic effects of endogenous GH. 相似文献2.
A.A. Kordyuk V.B. Zabolotnyy D.V. Evtushinsky D.S. Inosov T.K. Kim B. Büchner S.V. Borisenko 《The European physical journal. Special topics》2010,188(1):153-162
We review the search for a mediator of high-T
c superconductivity focusing on ARPES experiment. In case of HTSC cuprates, we summarize and discuss a consistent view of electronic
interactions that provides natural explanation of both the origin of the pseudogap state and the mechanism for high temperature
superconductivity. Within this scenario, the spin-fluctuations play a decisive role in formation of the fermionic excitation
spectrum in the normal state and are sufficient to explain the high transition temperatures to the superconducting state while
the pseudogap phenomenon is a consequence of a Peierls-type intrinsic instability of electronic system to formation of an
incommensurate density wave. On the other hand, a similar analysis being applied to the iron pnictides reveals especially
strong electron-phonon coupling that suggests important role of phonons for high-T
c superconductivity in pnictides. 相似文献
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4.
Evtushinsky DV Kordyuk AA Zabolotnyy VB Inosov DS Büchner B Berger H Patthey L Follath R Borisenko SV 《Physical review letters》2008,100(23):236402
We present a calculation of the Hall coefficient in 2H-TaSe(2) and 2H-Cu(0.2)NbS(2) based on their electronic structure extracted from angle-resolved photoemission spectra. The well-known semiclassical approach, based on the solution of the Boltzmann equation, yields the correct value for the normal-state Hall coefficient. Entering the charge density wave state results in the opening of the pseudogap and redistribution of the spectral weight. Accounting for this allows us to reproduce the temperature dependence of the Hall coefficient, including the prominent sign change, with no adjustable parameters. 相似文献
5.
A.A. Kordyuk V.B. Zabolotnyy B. Büchner 《Journal of Electron Spectroscopy and Related Phenomena》2010,181(1):44-47
Angle resolved photoemission spectroscopy (ARPES) has been playing a crucial role in understanding of physics behind high-temperature superconductivity. Our ARPES investigation of superconducting cuprates, performed over a decade and accomplished by very recent results, suggests a consistent view of electronic interactions in cuprates which provides natural explanation of both the origin of the pseudogap state and the mechanism for high-temperature superconductivity. Within this scenario, the spin-fluctuations play a decisive role in formation of the fermionic excitation spectrum in the normal state and are sufficient to explain the high transition temperatures to the superconducting state while the pseudogap phenomenon is a consequence of a Peierls-type intrinsic instability of electronic system to formation of an incommensurate density wave. In view of these results and their projection to numerous other materials, two general questions are arising: is the normal state in 2D metals ever stable and how does this intrinsic instability interplay with superconductivity? 相似文献
6.
Zabolotnyy VB Borisenko SV Kordyuk AA Fink J Geck J Koitzsch A Knupfer M Büchner B Berger H Erb A Lin CT Keimer B Follath R 《Physical review letters》2006,96(3):037003
The Cu substitution by Zn and Ni impurities and its influence on the mass renormalization effects in angle-resolved photoelectron spectra (ARPES) of Bi2Sr2CaCu2O8-delta is addressed. We show that the nonmagnetic Zn atoms have a much stronger effect in both the nodal and antinodal parts of the Brillouin zone than magnetic Ni. The observed changes are consistent with the behavior of the spin resonance mode as seen by inelastic neutron scattering in YBCO. This strongly suggests that the "peak-dip-hump" and the kink in ARPES on the one side and neutron resonance on the other are closely related features. 相似文献
7.
S.V. Borisenko A.A. Kordyuk V.B. Zabolotnyy T.K. Kim A.N. Yaresko H. Berger 《Journal of Physics and Chemistry of Solids》2011,72(5):562-564
We use angle-resolved photoemission spectroscopy to study bandwidth renormalization in layered superconductor 2H-NbSe2. Renormalization of the conduction band in comparison with the very similar 2H-TaSe2 is of the factor of two. We discuss the possibility that the Van Hove singularity could be responsible for this effect not only in dichalcogenides but also in pnictides. 相似文献
8.
Inosov DS Fink J Kordyuk AA Borisenko SV Zabolotnyy VB Schuster R Knupfer M Büchner B Follath R Dürr HA Eberhardt W Hinkov V Keimer B Berger H 《Physical review letters》2007,99(23):237002
Using high-resolution angle-resolved photoemission spectroscopy we have studied the momentum and photon energy dependence of the anomalous high-energy dispersion, termed waterfalls, between the Fermi level and 1 eV binding energy in several high-T_{c} superconductors. We observe strong changes of the dispersion between different Brillouin zones and a strong dependence on the photon energy around 75 eV, which we associate with the resonant photoemission at the Cu3p-->3d_{x;{2}-y;{2}} edge. We conclude that the high-energy "waterfall" dispersion results from a strong suppression of the photoemission intensity at the center of the Brillouin zone due to matrix element effects and is, therefore, not an intrinsic feature of the spectral function. This indicates that the new high-energy scale in the electronic structure of cuprates derived from the waterfall-like dispersion may be incorrect. 相似文献
9.
Geck J Borisenko SV Berger H Eschrig H Fink J Knupfer M Koepernik K Koitzsch A Kordyuk AA Zabolotnyy VB Büchner B 《Physical review letters》2007,99(4):046403
We report an angular resolved photoemission study of NaxCoO2 with x approximately 0.73 where it is found that the renormalization of the quasiparticle (QP) dispersion changes dramatically upon a rotation from GammaM to GammaK. The comparison of the experimental data to the calculated band structure reveals that the quasiparticle renormalization is most pronounced along the GammaK direction, while it is significantly weaker along the GammaM direction. We discuss the observed anisotropy in terms of multiorbital effects and point out the relevance of magnetic correlations for the band structure of NaxCoO2 with x approximately 0.75. 相似文献
10.
V.B. Zabolotnyy D.V. Evtushinsky A.A. Kordyuk D.S. Inosov A. Koitzsch A.V. Boris G.L. Sun C.T. Lin M. Knupfer B. Büchner A. Varykhalov R. Follath S.V. Borisenko 《Physica C: Superconductivity and its Applications》2009,469(9-12):448-451
Here we apply high resolution angle-resolved photoemission spectroscopy (ARPES) using a wide excitation energy range to probe the electronic structure and the Fermi surface topology of the Ba1?xKxFe2As2 (Tc = 32 K) superconductor. We find significant deviations in the low energy band structure from that predicted in calculations. A set of Fermi surface sheets with unexpected topology is detected at the Brillouin zone boundary. At the X-symmetry point the Fermi surface is formed by a shallow electron-like pocket surrounded by four hole-like pockets elongated in Γ?X and Γ?Y directions. 相似文献