91. New electronics for the surface detectors of the Pierre Auger ObservatoryT. Suomijärvi, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2017, objavljeni znanstveni prispevek na konferenci Ključne besede: surface detectors, Pierre Auger Observatory, electronics
Objavljeno v RUNG: 19.02.2018; Ogledov: 3375; Prenosov: 162
 Celotno besedilo (334,57 KB) |
92. The dynamic range of the AugerPrime Surface Detector: technical solution and physics reachAntonella Castellina, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2017, objavljeni znanstveni prispevek na konferenci Ključne besede: AugerPrime, Surface Detector, Pierre Auger Observatory
Objavljeno v RUNG: 16.02.2018; Ogledov: 3420; Prenosov: 174
Celotno besedilo (1,96 MB) |
93. Peculiar lightning-related events observed by the surface detector of the Pierre Auger ObservatoryRoberta Colalillo, Andrej Filipčič, Gašper Kukec Mezek, Ahmed Saleh, Samo Stanič, Marta Trini, Darko Veberič, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, 2017, objavljeni znanstveni prispevek na konferenci Ključne besede: Pierre Auger Observatory, surface detector, peculiar lightning-related events
Objavljeno v RUNG: 16.02.2018; Ogledov: 3475; Prenosov: 190
Celotno besedilo (3,10 MB) |
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97. Characterization of Mg low-index surfaces by first-principlesMiha Gunde, 2017, magistrsko delo Opis: In this work, three surfaces, namely, Mg(0001), Mg(10 ̄1 0) and Mg(11 ̄2 0) are investigated by means of Density Functional Theory and Generalized Gradient Approximation first-principle calculations. The surfaces have been characterized in terms of their interlayer distances, surface energies, Projected Density of States and Surface Core Level Shifts. Contrary to what was found in previous studies based on Density Functional Theory-Local Density Approximation, the use of Generalized Gradient Approximation exchange correlation functional unravels the oscillatory behavior of both interlayer distances and Surface Core Level Shifts of Mg(10 ̄1 0). Moreover,
the Projected Density Of States of un-reconstructed Mg(11 ̄2 0) exhibit the typical quantisation of electronic levels associated to a 2D-confinement of a 3D nearly-free electron gas, as observed in nano-wires, and a Peierls instability along the unconfined direction. Different possible reconstructions on Mg(11 ̄2 0) have then been investigated. In particular, it is found that the
surface energy of (2X1) and (3X1) reconstructions is almost degenerate and lower than the surface energy of the unreconstructed Mg(11 ̄2 0) surface. Because of the quasi-degeneracy of surface energies, Mg(11 ̄2 0) surface should be composed by a combination of all the quasi degenerate phases.
Ključne besede: Density Functional Theory, first-principle calculations, Mg surface, Surface Core-Level Shift, surface relaxation, surface reconstruction
Objavljeno v RUNG: 04.07.2017; Ogledov: 6066; Prenosov: 2104
Celotno besedilo (1,77 MB) |
98. Introduction to Electronic Properties and Dynamics of Organic Complexes as Self‐Assembled MonolayersMaddalena Pedio, 2017, samostojni znanstveni sestavek ali poglavje v monografski publikaciji Opis: Self‐assembled monolayers (SAMs) of organic‐conjugated transition metal complexes on surfaces is a focus of both device engineering and basic science, since it is a key factor in nearly all important aspects of device performances, including operation voltages, degradation, and efficiency. The huge amount of literature results related to the first monolayer, and reorganization and self‐assembling processes are due to the general accepted result that structural and chemical properties of the first monolayer are the key parameters for controlled thin film growth. Optical and magneto‐electronic properties are intimately connected, and the accurate determination of electronic levels, excitation, and relaxation dynamics is mandatory for the optimization of electronic, photovoltaic, and opto‐electronic devices. Quite a number of electronic states is generated by the interaction of light with
complex organic molecules. Time‐resolved spectroscopies are a new investigation tool
that gives the possibility of correctly addressing their origin and life time. Examples of prototypical systems are presented and discussed. We review on complementary techniques, trying to single out how different approaches are fundamental to fully characterize
these complex systems.
Ključne besede: self‐assembled monolayer (SAM), surface structures molecular layers, nanotechnology, electronic properties, spectroscopies, time resolved
Objavljeno v RUNG: 12.06.2017; Ogledov: 4577; Prenosov: 208
Celotno besedilo (5,78 MB) |
99. Time- and angle-resolved photoemission spectroscopy with optimized high-harmonic pulses using frequency-doubled Ti:Sapphire lasersSteffen Eich, Jurij Urbančič, 2014, izvirni znanstveni članek Opis: Time- and angle-resolved photoemission spectroscopy (trARPES) using femtosecond extreme ultraviolet high harmonics has recently emerged as a powerful tool for investigating ultrafast quasiparticle dynamics in correlated-electron materials. However, the full potential of this approach has not yet been achieved because, to date, high harmonics generated by 800 nm wavelength Ti:Sapphire lasers required a trade-off between photon flux, energy and time resolution. Photoemission spectroscopy requires a quasi-monochromatic output, but dispersive optical elements that select a single harmonic can significantly reduce the photon flux and time resolution. Here we show that 400 nm driven high harmonic extreme-ultraviolet trARPES is superior to using 800 nm laser drivers since it eliminates the need for any spectral selection, thereby increasing photon flux and energy resolution to <150 meV while preserving excellent time resolution of about 30 fs.
Ključne besede: angle-resolved photoemission spectroscopy, ARPES, high harmonic generation, ultrafast surface science
Objavljeno v RUNG: 20.04.2017; Ogledov: 5252; Prenosov: 0
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100. Self-amplified photo-induced gap quenching in a correlated electron materialMathias Stefan, Eich Steffen, Jurij Urbančič, 2016, izvirni znanstveni članek Opis: Capturing the dynamic electronic band structure of a correlated material presents a powerful capability for uncovering the complex couplings between the electronic and structural degrees of freedom. When combined with ultrafast laser excitation, new phases of matter can result, since far-from-equilibrium excited states are instantaneously populated. Here, we elucidate a general relation between ultrafast non-equilibrium electron dynamics and the size of the characteristic energy gap in a correlated electron material. We show that carrier multiplication via impact ionization can be one of the most important processes in a gapped material, and that the speed of carrier multiplication critically depends on the size of the energy gap. In the case of the charge-density wave material 1T-TiSe 2 , our data indicate that carrier multiplication and gap dynamics mutually amplify each other, which explains—on a microscopic level—the extremely fast response of this material to ultrafast optical excitation.
Self-amplified photo-induced gap quenching in a correlated electron material. Available from: https://www.researchgate.net/publication/308804379_Self-amplified_photo-induced_gap_quenching_in_a_correlated_electron_material [accessed Apr 20, 2017].
Ključne besede: high harmonic generation, charge-density wave material, 1T-TiSe2, non-equilibrium electron dynamics, ultrafast surface science
Objavljeno v RUNG: 20.04.2017; Ogledov: 5527; Prenosov: 0
Gradivo ima več datotek! Več... |
