169 research outputs found
Feiras livres como alternativa de comercialização de produtos agroecológicos da agrofloresta.
Self-Energy Effects on the Low- to High-Energy Electronic Structure of SrVO3
The correlated electronic structure of SrVO3 has been investigated by
angle-resolved photoemission spectroscopy using in-situ prepared thin films.
Pronounced features of band renormalization have been observed: a sharp kink
~60 meV below the Fermi level (EF) and a broad so-called "high-energy kink"
~0.3 eV below EF as in the high-Tc cuprates although SrVO3 does not show
magnetic fluctuations. We have deduced the self-energy in a wide energy range
by applying the Kramers-Kronig relation to the observed spectra. The obtained
self-energy clearly shows a large energy scale of ~0.7 eV which is attributed
to electron-electron interaction and gives rise to the ~0.3 eV "kink" in the
band dispersion as well as the incoherent peak ~1.5eV below EF. The present
analysis enables us to obtain consistent picture both for the incoherent
spectra and the band renormalization.Comment: 5 pages, 3 figure
Giant Rashba splitting of quasi-1D surface states on Bi/InAs(110)-(21)
Electronic states on the Bi/InAs(110)-(21) surface and its
spin-polarized structure are revealed by angle-resolved photoelectron
spectroscopy (ARPES), spin-resolved ARPES, and density-functional-theory
calculation. The surface state showed quasi-one-dimensional (Q1D) dispersion
and a nearly metallic character; the top of the hole-like surface band is just
below the Fermi level. The size of the Rashba parameter ()
reached quite a large value (5.5 eV\AA). The present result would provide
a fertile playground for further studies of the exotic electronic phenomena in
1D or Q1D systems with the spin-split electronic states as well as for advanced
spintronic devices.Comment: 8 pages (double column), 7 figures and 1 tabl
An energy scale directly related to superconductivity in the high- cuprate superconductors: Universality from the Fermi arc picture
We have performed a temperature dependent angle-resolved photoemission
spectroscopy (ARPES) study of the tri-layer high- cuprate superconductor
(HTSC) BiSrCaCuO (Bi2223), and have shown that
the \textquotedblleft effective\textquotedblright superconducting (SC) gap
defined at the end point of the Fermi arc and the (=
110 K) approximately satisfies the weak-coupling BCS-relationship
2 = 4.3. Combining this result with previous
ARPES results on single- and double-layer cuprates, we show that the
relationship between 2 = 4.3 holds for various
HTSCs. Furthermore, at , the quasi-patricle width at the end
point of the Fermi arc is found to coincide with , consistent
with the context of Planckian dissipation.Comment: 5 pages, 4 figure
Effect of electron-phonon coupling in the ARPES spectra of the tri-layer cuprate BiSrCaCuO
Angle-resolved photoemission spectroscopy using tunable low energy photons
allows us to study the quasi-particle (QP) dispersions of the inner and outer
CuO2 planes (IP and OP) separately in the tri-layer cuprate
BiSrCaCuO (Bi2223). The kink energy of the OP
band is 70 meV, as observed in various high- cuprates, while that
of the IP band is as large as 100 meV in the superconducting (SC) state. This
large kink energy is attributed to the 35 meV buckling mode plus the
large ( 60 meV) SC gap of IP. The IP band also shows a weak kink feature
at 70 meV in the SC state. The latter feature can be explained either by the 70
meV half-breathing mode or by the 35 meV buckling-phonon mode plus the
40 meV SC gap of OP if interlayer scattering of QP is involved.Comment: 5 pages, 2 figure
- …