7 research outputs found
Revealing the Orbital Composition of Heavy Fermion Quasiparticles in CeRu2Si2
We present a resonant angle-resolved photoemission spectroscopy (ARPES) study of the electronic band structure and heavy fermion quasiparticles in CeRu2Si2. Using light polarization analysis, considerations of the crystal field environment and hybridization between conduction and f electronic states, we identify the d-electronic orbital character of conduction bands crossing the Fermi level. Resonant ARPES spectra suggest that the localized Ce f states hybridize with eg and t2g states around the zone center. In this fashion, we reveal the orbital structure of the heavy fermion quasiparticles in CeRu2Si2 and discuss its implications for metamagnetism and superconductivity in the related compound CeCu2Si2
Letter Ruling 99-1: Electronic Retailers
The synthesis and
characterization of a set of redox-active iron
and ruthenium alkynyl complexes of general formula [[M]ÂCl<sub>(1â<i>p</i>)</sub>{CîŒCC<sub>6</sub>H<sub>5â<i>m</i></sub>(CîŒCFlu)<sub><i>m</i></sub>}<sub>(1+<i>p</i>)</sub>]Â[PF<sub>6</sub>]<sub><i>n</i></sub> are
reported (<i>n</i> = 0â1; <i>m</i> = 1â2;
[M] = [FeÂ(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)Â(Îș<sup>2</sup>-dppe)] and <i>p</i> = 1 or [M] = [<i>trans</i>-RuÂ(Îș<sup>2</sup>-dppe)<sub>2</sub>] and <i>p</i> = 0â1). The linear and third-order nonlinear optical properties
of these new organometallic complexes featuring phenylalkynyl ligands
functionalized by 2-fluorenyl (Flu) groups were studied in their stable
redox states. Their first electronic transitions are assigned with
the help of DFT calculations. We show here that these compounds possess
significant third-order NLO responses in the near-IR range for molecules
of their size. In particular, the remarkably large 2PA activities
of the new RuÂ(II) compounds in the 600â800 nm range (<i>Z</i>-scan) make them attractive nonlinear chromophores. Structureâproperty
studies emphasize the importance of para- versus meta-connection of
the 2-fluorenylethynyl units on the phenylalkynyl core and reveal
that upon progressing from mono- to bis-alkynyl complexes a further
increase of the 2PA cross section can be obtained while maintaining
linear transparency in the visible range
Panoramic SETI: Program Update and High-Energy Astrophysics Applications
Optical SETI (Search for Extraterrestrial Intelligence) instruments that can
explore the very fast time domain, especially with large sky coverage, offer an
opportunity for new discoveries that can complement multimessenger and time
domain astrophysics. The Panoramic SETI experiment (PANOSETI) aims to observe
optical transients with nanosecond to second duration over a wide field-of-view
(2,500 sq.deg.) by using two assemblies of tens of telescopes to
reject spurious signals by coincidence detection. Three PANOSETI telescopes,
connected to a White Rabbit timing network used to synchronize clocks at the
nanosecond level, have been deployed at Lick Observatory on two sites separated
by a distance of 677 meters to distinguish nearby light sources (such as
Cherenkov light from particle showers in the Earth's atmosphere) from
astrophysical sources at large distances. In parallel to this deployment, we
present results obtained during four nights of simultaneous observations with
the four 12-meter VERITAS gamma-ray telescopes and two PANOSETI telescopes at
the Fred Lawrence Whipple Observatory. We report PANOSETI's first detection of
astrophysical gamma rays, comprising three events with energies in the range
between 15 TeV and 50 TeV. These were emitted by the Crab
Nebula, and identified as gamma rays using joint VERITAS observations.Comment: 9 pages, 5 figures, SPIE Astronomical Telescopes + Instrumentation
conference, 2022, Montr\'eal, Qu\'ebec, Canad
Linear and Third-Order Nonlinear Optical Properties of Fe(n5-C5Me5)(k2-dppe)- and trans-Ru(k2-dppe)2-Alkynyl Complexes Containing 2-Fluorenyl End Groups
The synthesis and characterization of a set of redox-active iron and ruthenium alkynyl complexes of general formula [[M]Cl(1âp){CâĄCC6H5âm(CâĄCFlu)m}(1+p)][PF6]n are reported (n = 0â1; m = 1â2; [M] = [Fe(η5-C5Me5)(Îș2-dppe)] and p = 1 or [M] = [trans-Ru(Îș2-dppe)2] and p = 0â1). The linear and third-order nonlinear optical properties of these new organometallic complexes featuring phenylalkynyl ligands functionalized by 2-fluorenyl (Flu) groups were studied in their stable redox states. Their first electronic transitions are assigned with the help of DFT calculations. We show here that these compounds possess significant third-order NLO responses in the near-IR range for molecules of their size. In particular, the remarkably large 2PA activities of the new Ru(II) compounds in the 600â800 nm range (Z-scan) make them attractive nonlinear chromophores. Structureâproperty studies emphasize the importance of para- versus meta-connection of the 2-fluorenylethynyl units on the phenylalkynyl core and reveal that upon progressing from mono- to bis-alkynyl complexes a further increase of the 2PA cross section can be obtained while maintaining linear transparency in the visible range
Revealing the Orbital Composition of Heavy Fermion Quasiparticles in CeRu 2 Si 2
We present a resonant angle-resolved photoemission spectroscopy (ARPES) study of the electronic band structure and heavy fermion quasiparticles in CeRu2Si2. Using light polarization analysis, considerations of the crystal field environment and hybridization between conduction and f electronic states, we identify the d-electronic orbital character of conduction bands crossing the Fermi level. Resonant ARPES spectra suggest that the localized Ce f states hybridize with eg and t2g states around the zone center. In this fashion, we reveal the orbital structure of the heavy fermion quasiparticles in CeRu2Si2 and discuss its implications for metamagnetism and superconductivity in the related compound CeCu2Si