Search results for "Condensed Matter Physic"
showing 10 items of 10713 documents
Recent experiments at the JYFLTRAP Penning trap
2020
AbstractThe JYFLTRAP double Penning trap mass spectrometer at the Ion Guide Isotope Separator On-Line (IGISOL) facility offers excellent possibilities for high-precision mass measurements of radioactive ions. Around 400 atomic masses, including around 50 isomeric states, have been measured since JYFLTRAP became operational. JYFLTRAP has also been used as a high-resolution mass separator for decay spectroscopy experiments as well as an ion counter for fission yield studies. In this contribution, an overview of recent activities at the JYFLTRAP Penning trap is given, with a focus on nuclei discussed in the PLATAN2019 meeting.
Numerical construction of the density-potential mapping
2018
We demonstrate how a recently developed method Nielsen et al. [Nielsen et al., EPL 101, 33001 (2013)] allows for a comprehensive investigation of time-dependent density functionals in general, and of the exact time-dependent exchange-correlation potential in particular, by presenting the first exact results for two- and three-dimensional multi-electron systems. This method is an explicit realization of the Runge–Gross correspondence, which maps time-dependent densities to their respective potentials, and allows for the exact construction of desired density functionals. We present in detail the numerical requirements that makes this method efficient, stable and precise even for large and rap…
Exploring integration prospects of opal-based photonic crystals
2003
Different methods of functionalisation of thin opal films are discussed, including synthesis of opals on pre-patterned substrates, post-synthesis electron beam lithography, preparation of opals with heterogeneous photonic band gap structure and integrating opals with light sources. These approaches have been tested experimentally and key technological problems have been identified.
Optical Absorption of Excimer Laser‐Induced Dichlorine Monoxide in Silica Glass and Excitation of Singlet Oxygen Luminescence by Energy Transfer from…
2021
An optical absorption (OA) band of interstitial dichlorine monoxide molecules with peak at 4.7 eV and halfwidth 0.94 eV is identified in F2 laser - irradiated (photon energy=7.9 eV) synthetic silica glass bearing both interstitial O2 and Cl2 molecules. Alongside with intrinsic defects, this OA band can contribute to solarization of silica glasses produced from SiCl4. While the formation of ClClO is confirmed by its Raman signature, its structural isomer ClOCl may also contribute to this induced OA band. Thermal destruction of this band between 300C and 400C almost completely restores the pre-irradiation concentration of interstitial Cl2. An additional weak OA band at 3.5 eV is tentatively a…
Near‐IR Radiation‐Induced Attenuation of Aluminosilicate Optical Fibers
2021
The X-ray radiation-induced attenuation (RIA) growth kinetics are studied online in different single-mode aluminosilicate optical fibers in the near-IR (NIR) domain to evaluate their potential in terms of dosimetry. The optical fibers differ by Al contents, core sizes, drawing parameters, and also by a preform deposition process. The data show no dependence of the RIA on all these parameters, a positive result for the design of point or distributed radiation detectors exploiting RIA to monitor the dose. The RIA growth rate is unchanged for dose rates changing from 0.073 to 6.25 Gy(SiO2) s−1, and the RIA linearly increases with the dose up to 2 kGy(SiO2). Small but noticeable RIA changes are…
Ge quantum well plasmon-enhanced quantum confined Stark effect modulator
2014
ABSTRACTWe theoretically and experimentally investigate a novel modulation concept on silicon (Si) based on the combination of quantum confinement and plasmon enhancement effects. We experimentally study the suitability of Ge/SiGe quantum wells (QWs) on Si as the active material for a plasmon-enhanced optical modulator. We demonstrate that in QW structures absorption and modulation of light with transverse magnetic (TM) polarization are greatly enhanced due to favorable selection rules. Later, we theoretically study the plasmon propagation at the metal-Ge/SiGe QW interface. We design a novel Ge/SiGe QW structure that allows maximized overlap between the plasmonic mode and the underlying Ge/…
Optical and structural properties of Al 2 O 3 /ZnO nanolaminates deposited by ALD method
2014
International audience; We report on the investigation of optical and structural properties of Al2O3/ZnO nanolaminates. The nanolaminates were deposited on Si and glass substrates by Atomic layer deposition method. Structural properties of nanolaminates were studied by SEM, GIXRD, and AFM. Optical characterization was performed by transmittance and photoluminescence spectroscopy. Complex analysis of monolayer properties was done by ellipsometry. Optical constants for Al2O3 and ZnO monolayer were calculated.
Atomic layer deposition of AlN from AlCl3 using NH3 and Ar/NH3 plasma
2018
The atomic layer deposition (ALD) of AlN from AlCl3 was investigated using a thermal process with NH3 and a plasma-enhanced (PE)ALD process with Ar/NH3 plasma. The growth was limited in the thermal process by the low reactivity of NH3, and impractically long pulses were required to reach saturation. Despite the plasma activation, the growth per cycle in the PEALD process was lower than that in the thermal process (0.4A ° vs 0.7A ° ). However, the plasma process resulted in a lower concentration of impurities in the films compared to the thermal process. Both the thermal and plasma processes yielded crystalline films; however, the degree of crystallinity was higher in the plasma process. The…
Long-transient conoscopic pattern technique
1999
0038-1098; Recent results on laser induced anisotropy in terbium gallium garnet are extended to the dynamic regime. We observed that the characteristic conoscopic pattern formation time presents a quadratic dependence on the beam size. The observed pattern intensity is accounted for by a simple analytical formula. The transient refractive index change due to thermal stress in the terbium gallium garnet is determined. (C) 1999 Elsevier Science Ltd. All rights reserved.
Unravelling the Intertwined Atomic and Bulk Nature of Localised Excitons by Attosecond Spectroscopy
2021
The electro-optical properties of most semiconductors and insulators of technological interest are dominated by the presence of electron-hole quasi-particles, called excitons. The manipulation of excitons in dielectrics has recently received great attention, with possible applications in different fields including optoelectronics and photonics. Here, we apply attosecond transient reflection spectroscopy in a sequential two-foci geometry and observe sub-femtosecond dynamics of a core-level exciton in bulk MgF2 single crystals. Furthermore, we access absolute phase delays, which allow for an unambiguous comparison with theoretical calculations. Our results show that excitons surprisingly exhi…