The goal of ITER is to demonstrate the scientific and technical feasibility of fusion energy, building on several decades of worldwide research on the physics and technology of magnetic confinement. ITER is the world’s largest and most complex energy research project undertaken with the prospect of an inexhaustible energy respectful of the environment. To meet this challenge an international...
The properties of materials are determined by the positions of the atoms, their chemical nature and the bonding between them. Therefore, reaching atomic resolution in 3D has been the ultimate goal in the field of electron tomography for many years. One of the possibilities to perform electron tomography with atomic resolution is by applying reconstruction algorithms based on compressive...
The recent developments in the generation of optical attopulses suggest that it will soon become experimentally feasible to induce and subsequently directly probe ultrafast charge transfer between the end moieties of modular molecules. One ultrafast pulse creates a non-stationary state of the neutral or of the cation, that can be probed by a second pulse. Such experiments would allow...
We start from a recent breakthrough, Park, J. et al., Phys. Rev. X 5.2 (2015): 021024: the first experimental demonstration of the transition of a high pressure plasma to a state of magnetic condensate. A magnetic condensate is a system where the magnetic field is completely expelled from a plasma, forming a sharp transition: the plasma behaves like a drop of liquid with a definite surface....
Our understanding of the structure of the atomic nucleus, previously based on the information collected on stable nuclei, has been severely challenged in the last thirty years, since systematic research on nuclei far from stability was started. The unusual neutron-to-proton ratio of those systems revealed special features of the underlying nucleon-nucleon interaction, reflected in...
Understanding and predicting the viscoelastic response of polymer melts or concentrated solutions from the knowledge of molecular architecture represents a very active field of research with important challenges. Our first objective is to develop a general coarse-grained model for predicting the viscoelastic properties of linear and branched polymers. Based on the tube theory proposed by de...
3D model of a reverse-vortex flow gliding arc plasmatron
G. Trenchev, St. Kolev, A. Bogaerts
PLASMANT research group, Department of Chemistry, University of Antwerp, Universiteitsplein 1, Wilrijk, Belgium Faculty of Physics, Sofia University, 5 James Bourchier blvd, 1164 Sofia, Bulgaria
georgi.trenchev@uantwerpen.be
This study employs a comprehensive computational model for a 3D...
Pairing is an essential ingredient to understand the low-energy structure of atomic nuclei [1]. Whereas the Bardeen-Cooper-Schrieffer (BCS) Ansatz has proven very successful in capturing the collective nature of the nuclear pair excitations, there remain some important deficiencies related to finite-size effects of the nuclear many-body problem [1]. Richardson and Gaudin (RG) have shown that...
Brownian relaxation in colloidal suspensions has been observed in different susceptibilities such as shear moduli, viscosities or diffusion coefficients [1-6]. We present Brownian relaxation times obtained by Small Angle Oscillatory Shear (SAOS) measurements on suspensions consisting of two types of a low-molecular weight glass former (Diglycidyl Esther of Bisphenol A) filled with silica...
Thin films constitute the building blocks of a large number of modern technologies including protective coatings, microelectronic devices, bio-responsive membranes and photovoltaic cells. These nano-layers exhibit vastly different mechanical properties from their bulk counterpart. New measurement techniques are therefore required to accurately and reliably measure the mechanical properties of...
Optical-lattice experiments have recently succeeded in probing the geometry of 2D Bloch bands with cold neutral atoms. Beyond these local geometrical effects, which are captured by the Berry curvature, 2D Bloch bands may also display non-trivial topology, a global property captured by a topological invariant (e.g. the first Chern number). Such topological properties have dramatic consequences...
SQUID-on-tip (SOT) is the most sensitive detector of small magnetic moments to date [1]. We analyze the performance of such nano-sized SOT (Fig. 1) in the presence of the magnetic field, using the state-of-the-art three dimensional (3D) simulations within the phenomenological Ginzburg-Landau (GL) theory. Based on the observed behavior of the superconducting order parameter in the SOT, the...
The electron impact ionization of the metastable state 1s2s3S of helium is particularly important in the modelling of plasmas, and, as a simple system, is also a benchmark for theories. Indeed, there are many theoretical studies devoted to the calculation of the ionization cross section [2, 3], ranging from Born calculations to sophisticated close-coupling calculations. In contrast, only a few...
Ion cyclotron resonance heating (ICRH) is a routinely used method to bring plasmas to fusion relevant temperatures in magnetic confinement fusion machines (see e.g. [1]). Properly modelling the dielectric response is a challenge both from the physics and the computational point of view. More often than not simplifications are made, first of all by truncating the dielectric tensor at the...
Since the introduction of high brightness and high efficiency light emitting diodes (LEDs), solid state lighting is ready to take over the lighting and display market. While the original concept of white LEDs (wLEDs) is based on a blue-emitting chip on which a light-converting phosphor is coated, a new approach has gained interest in the last decade [1] (see figure 1). In this so-called remote...
Our society is using ever more complex materials which often involve nanometre-scale morphology. From impurities or minor alloying additions at grain boundaries to nanostructured (composite) materials or the naturally nanostructured electrochemical interfaces: The detailed knowledge of structural and elemental distributions in the bulk as well as on/along the surfaces or interfaces becomes...
Self-assembled thiol monolayers (SAMs) are molecular assemblies of organic constituents formed spontaneously by the adsorption process of thiol molecules in liquid or vapor phase on metal or metal oxide surfaces [1]. On the one hand, chemisorption of the adsorbate head group onto metal surfaces at the metal-SAM nano-interface leads to a strong sulfur-metal bond, on the other hand, interactions...
We investigate multiqubit permutation-symmetric states with maximal entropy of entanglement. Such states can be viewed as particular spin states, namely anticoherent spin states. Using the Majorana representation of spin states in terms of points on the unit sphere, we analyze the consequences of a point-group symmetry in their arrangement on the quantum properties of the corresponding state...
Metal-Organic Frameworks (MOFs) are crystalline porous materials constructed of metal ions connected by organic linkers. These materials possess many interesting features, like well-defined pore size, pore shape and ultra-high porosity. A characteristic example of MOFs with one dimensional pores is Al-MIL-53 ([Al(OH)(BDC), BDC = terephthalate or 1,4-benzenedicarboxylate]. The 3D framework of...
We study the possibility of chaos for the Bohmian dynamics when the wave function is stationary. Examples of stationary wave functions are given for which there is chaos, as demonstrated by numerical computations, for one particle moving in 3 spatial dimensions and for two and three entangled particles in 2 dimensions. What is important for the amount of chaos is the overall complexity of the...
Bimetallic AuxAg1-x clusters with various compositions (x = 0.9, 0.7, 0.4 and 0.2) grown in the gas phase and deposited on amorphous SiO2 wafers and TEM grids were characterized by a combination of aberration corrected high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) and grazing-incidence small-angle X-ray scattering (GISAXS). Clusters with an average...
In the present work, we present a computational model for studying reactive and partially ionized plasmas in thermo-chemical nonequilibrium under the effect of electromagnetic fields, such as in astrophysics or fusion-related applications. In order to tackle the non-equilibrium effects present in such a plasma, we adopt a multi-fluid formulation including electromagnetic effects. Multi-fluid...
The confinement of light to material interfaces and thin layers, i.e., the propagation of surface waves along metal-dielectric interfaces or guided waves along dielectric waveguides, enables a multitude of photonic applications in (bio)sensing, optical circuitry and optical actuation. Several research groups try to enhance our control on the propagation of confined light by making use of...
Ion cyclotron wall conditioning (ICWC) is being developed for ITER as a baseline conditioning technique in which the ion cyclotron heating and current drive system will be employed to produce and sustain the current-less conditioning plasma. The TOMAS project (TOroidal MAgnetized System, operated at the FZ-Juelich, Germany) proposes to explore several key aspects of ICWC. This project stands...
We present the recent progress in the development of a hydrogen maser in the TE111 mode. Hydrogen masers use the transition at 1420.405 MHz between the two hyperfine levels F = 0 and F = 1 of the 1s1/2 ground state of the hydrogen atom [1]. Standard hydrogen masers are heavy devices which are based on the use of a TE011 cylindrical cavity with dimensions of the order of 27 cm [1]. In contrast,...
While attempting to identify the particle content of dark matter, one often assumes that Dark Matter is a particle arising from a supersymmetric theory. When a population thereof becomes gravitationally bound in the Sun, mutual annihilations can produce a flux of neutrinos. By estimating how this flux would be recognised by a neutrino telescope one can then make conclusions about whether the...
Small atomic objects such as molecules and atomic clusters play a key role in bottom up approaches to tailor properties of matter and constitute fundamental building blocks for the synthesis of new advanced materials. Due to quantum confinement effects, small clusters with a countable number of atoms show entirely new physical phenomena without equivalent in bulk materials [1]. The strong size...
Hadron therapy is increasing worldwide for treating some radio-resistant tumours due to its more advantageous depth dose deposition, less lateral spread and better sparing of healthy tissues close to the irradiated target as compared to photon or electron beams. Besides these favourable physical properties, ion beams offer potential biological advantages over protons making them even more...
Recently, frequency comb generation using time modulated planar graphene sheets was introduced by Ginis et al. Here we show that this process is more e?fficient in a graphene ribbon lattice than in a planar structure. To do so we exploit the plasmonic resonances of the lattice, which are very sensitive to the graphene doping level. By dynamically changing this doping the transmission becomes...
Ever since the polaron concept was introduced by Landau in 1933 to describe the quasiparticle arising from the interaction between an electron and the polarization cloud it drags along while moving in a polar crystal, a wide variety of physical systems have been mapped on the polaron problem. Among these realizations, one that has been the focus of much attention in the recent years is the BEC...
The main objective of the stellarator Wendelstein 7-X (W7-X) is to show the potential of optimized stellarators. The main heating system is ECRH up to 10 MW steady-state at 140 GHz. NBI is also foreseen in pulses up to 10 s. An important aim of W7-X is to demonstrate fast ion confinement at volume averaged beta values up to 5%, corresponding to plasma densities above 1020 m-3. Mimicking the...
Accurate identification of jets originating from b quarks has been of prime importance for many measurements and searches in CMS. The development of a charm tagger, a tool to identify jets initiated by charm quarks, will be no different, allowing analysts to broaden the spectra of their research. We detail the technique that was used to train an MVA–based discriminator to tag charm jets, its...
About 1% of the world population is affected by an allergy for peanuts which is the most common cause of fatal-food-related anaphylaxis. Due to the high risk of exposure and the fact that doses of a few milligrams can cause such an allergic reaction, a lot of research has been done towards the detection of these immunogenic proteins. The protein Ara h1 was identified as the culprit in 95% of...
The use of infrared emitting persistent phosphors for medical imaging is an exciting application in the field of persistent luminescence [1]. Current research focuses on host materials doped with Mn2+ or Cr3+, as these transition metals show emission at wavelengths larger than 600 nm, which falls in the tissue transparency window [2]. In this work, we focus on Cr-doped LiGa5O8 (LGO), which is...
Lithium-ion batteries are considered as power source for electric vehicles (EV), as well as off-grid energy storage for power plant. These specific applications drive the research on high energy density, cost-effective, safe and environmental friendly battery materials. Silicon, the earth crust’s 3rd abundant material, shows very promising properties for use in battery anodes, such as the...
At hadron colliders, top quarks - the heaviest elementary particles known- are dominantly produced in pairs (ttbar), a production mechanism having been discovered more than twenty years ago at Tevatron, Fermilab. Although the ttbar process has already entered the domain of 'precision' Physics, especially with the advent of the multi-TeV energies at the CERN Large Hadron Collider, there still...
Modelling of stellar atmospheres requires various detailed and accurate data on different processes such as the mutual neutralization (MN) of cation-anion pairs that can affect atomic species of interest. Indeed, neutralization reactions play an important role in atmospheric and astrophysical processes. Furthermore, there is a strong demand from the astrochemical community for information...
Since the discovery of the exchange bias phenomenon, which is a shift in the hysteresis loop when coupling a ferromagnet (FM) to an antiferromagnet (AFM), a lot of scientific efforts were made in order to explain this effect. Although exchange bias is widely used in spin valves, it’s origin is not yet completely understood and sometimes obscured by the disorder in the antiferromagnetic grains...
X-ray emission lines from accreting sources, most notably the K_alpha- and K_beta-lines from iron ions, have observed widths and shifts which imply an origin very close to the compact object in many cases [1]. The inferred line origin can be near either the innermost stable circular orbit or the event horizon in the case of a black hole. The intensity of these lines can provide insight into...
Atomic Layer Deposition (ALD) is a technique for the deposition of uniform thin films with a thickness control on the atomic scale. Due to the self-limited nature of the surface reactions, it is possible to grow uniform thin films with an excellent conformality. Therefore ALD has become a key method for coating and functionalizing 3D large surface area structures such as anodized alumina...
For more than 40 years now, single wavelength and spectroscopic ellipsometry have been intensively used to determine optical properties as well as thickness of multilayered materials (see e.g. [1]). Principal components analysis (PCA) and hierarchical cluster analysis (HCA) are multivariate analysis methods respectively used for dimension data reduction and classification, respectively [2, 3]....
Anions play important roles in the chemistry of various astrophysical environments ranging from planetary and stellar atmospheres to interstellar clouds [1-3]. A key reaction for the ionization balance in those media is the Mutual Neutralization (MN) of atomic or molecular anions and cations [3]: A+ + B− → A + B.
MN studies with atomic ions have so far mainly been limited to collision...
Reactive DC magnetron sputtering is a common technique to deposit compound films. Starting from an elemental metal target, the composition on the substrate can be altered by adjusting the reactive gas flow. However, at given sputtering conditions, a transition in operating conditions is noticed at critical reactive gas flow rates inducing the well-known hysteresis effect during reactive...
M. Tripsky1,2, T. Wauters1, A. Lyssoivan1
1Laboratory for Plasma Physics-ERM/KMS, 1000 Brussels, Belgium
2Ghent University, Department of Applied Physics, 9000 Ghent, Belgium
The RFdinity1d3v particle-in-cell Monte Carlo collision (PIC-MCC) model is used to study discharges produced and sustained by ion cyclotron range of frequency (ICRF) waves in absence of plasma current for...
The increasing world energy demand in combination with the dependency on limited fossil fuels results in a lot of stress on global climate and the geopolitical situation. Most energy scenarios emphasise the importance of innovations not only on the generating side e.g. by renewable energy, but also on the consumer side e.g. by more energy efficient lighting or personal electronics devices....
The preliminary design of an Ion Cyclotron Range of Frequency traveling-wave antenna, based on a comb-line structure in a resonant ring, is presented. The design maximize the coupled power to the inhomogeneous plasma giving an operation band characterized by an almost perfect matching to the generator(s) with a simple feeding system. The antenna system is suitable for the operation in a fusion device.
We overview the current and planned experiments in high-energy hadron physics, which are aimed to investigate unresolved issues in our understanding of the intrinsic structure of the strong interacting particles. Special emphasis is put on the spin- and transverse momentum- dependent correlations of the fundamental constituents of the nucleons - quarks and gluons.
I will present a generic search for a heavy scalar boson using 13 TeV proton-proton collision data acquired by the CMS experiment in 2015. Events in the decay channel H->ZZ->2l2v are selected from data corresponding to an integrated luminosity of 2.3 fb^-1. An analysis of the reconstructed transverse mass and missing transverse energy is performed in different event categories, and limits are...
Dark matter is necessary to explain multiple astrophysical observations that appear to be the result of the presence of mass which cannot be seen using light or other electromagnetic waves. One way to search for dark matter is through production at colliders, such as the LHC at CERN. A search for new physics has been performed at the CMS experiment using events having large missing transverse...
A search for new physics is performed using events with multileptons ( ≥ 3 electrons or muons) in the final state using the CMS detector. Results are based on a sample of proton-proton collisions at a centre-of-mass energy of 13 TeV at the LHC corresponding to an integrated luminosity of 2.3 fb−1. Search regions have been defined by the number of b-tagged jets, missing transverse energy,...
In recent years there has been an increased interest in the use of a medium resolution semiconductor CdZnTe (CZT) detector for gamma-ray spectroscopy and in safeguards applications. However, due to the different mobility and lifetime of electrons and holes in the crystal’s sensitive volume, a CZT detector shows an asymmetrical peak characterized by low-energy tailing.
The type and settings...
With this work we aim at studying with more details the highly multiscale kinetic process of magnetic reconnection occurring at the dayside magnetopause. This process is partially responsible for geomagnetic substorms and capable of producing highly energetic particles. In particular, we present results on the electron dynamics from fully kinetic Particle-in-Cell (PIC) simulations. The...
Radiative transfer simulations that describe the propagation of light from and through astronomical objects are gaining more and more importance when interpreting observational data. One observational signature that has not been fully exploited is polarization, which is mainly due to scattering off electrons and dust grains. Recently, this potential is being realized, and a growing number of...
This poster will cover the novel technology used in the SoLid experiment and will discuss the ?first results of the SubModule1 prototype.
Ionizing radiation exposure represents one of the most important health risk for astronauts in space. Radiation dose rates in space are typically more than two orders of magnitude higher than on Earth. Therefore, it is of primordial importance to monitor the astronauts’ radiation doses. However, space dosimetry is very challenging due to the high complexity of the space radiation field...
Johan van der Tol, Dewei Jia, Yejun Li, Valeriy Chernyy, Joost Bakker, Minh Nguyen, Ewald Janssens
Silver clusters composed of a few atoms are very interesting for photography and redox catalysis. This is mainly because of their size dependent optical properties and a strong interplay between their geometric and electronic structure, which has a discrete density of states.
Despite the...
Metal doped silicon clusters have attracted a lot of interest the past decades. Fundamental understanding of small metal doped silicon clusters and their bonding is relevant for nanoscale silicon components in optoelectronic and semiconductor devices. Here, we have explored the geometric, electronic and magnetic properties of cationic doped silicon clusters (Si_nAg^+ (n = 6−15), Si_nAu^+ (n =...
Abstract
We present the results of the characterization of the topological insulator (TI) Bi2Te3 in four different environments using scanning probe microscopy (SPM) based techniques. Upon exposure to air at room temperature the cleaved surface of the pristine Bi2Te3 is observed to be strongly modified during scanning tunneling microscopy (STM) measurements. Remarkably, there is no surface...
We derive and solve a markovian master equation for the internal dynamics of an ensemble of indistinguishable two-level atoms including all effects related to the quantization of their motion [1]. Our equation provides a unifying picture of the consequences of recoil and indistinguishability of atoms beyond the Lamb-Dicke regime on both their dissipative and conservative internal dynamics, and...
Luminescent materials or phosphors play an important role in many everyday applications such as lighting and displays. These phosphors consist of a host compound doped with luminescent ions called activators. Almost all the commercial phosphors used today are activated by lanthanide ions[1]. However, a few years ago the rare-earth market was struck by a crisis when China, the leading exporter...
Luminescent materials, also known as phosphors, are an essential component of white light emitting diodes (LEDs). White LEDs consist of a blue emitting LED chip and one or more phosphor materials which convert part of the blue light to longer wavelengths. In order to mimic the spectrum of a black body radiator as closely as possible, luminescent materials showing broad emission bands are used....
The CERN engineering and physics departments designed and built the new Gamma Irradiation Facility (GIF++) which is fully operational since March, 2015. The GIF++ is motivated by strong needs from the LHC detector and accelerator communities to perform long term ageing studies. It is a unique facility where high energy charged particles beam (mainly muons) are combined with a flux of photons...
The goal of the ESA ITT project AO-1-8384-15-1-NB VSWMC-Part 2 is to further develop the Virtual Space Weather Modelling Centre (VSWMC), building on the Phase 1 prototype system and focusing on the interaction with the ESA SSA SWE system. The objective and scopes of this project include:
The efficient integration of new models and new model couplings, including a first demonstration of...
The Mercator telescope is a 1.2m semi-automatic telescope placed at the Roque de los Muchachos observatory at the Canary Islands. The permanent availability allows us to occupy a specific niche in observational astrophysics: the possibility to make long-term time-series. To exploit this fully we developed a modern instrument programme. I will start this contribution with a review of our...
The Voltage Control of Magnetic Anisotropy (VCMA) effect allows to control a magnetic bit by means of an electric field [1] instead of high currents, enabling a much lower power consumption. State-of-the-art Magnetic Tunnel Junction (MTJ) material stacks using mostly MgO as a dielectric have been screened for VCMA applications [1,2]. The MgO VCMA effect is currently too weak for use in logic...
The field of materials design occupies itself with the search for materials that exhibit specific properties. Such materials can be obtained by finetuning promising candidates using defects or by synthesizing entirely new materials based on experience from nature. This requires a detailed understanding of the nanoscale features which gives rise to these properties, as well as considerable...
Jeroen E. SCHEERDER1 , Bart RAES2, Marius V. COSTACHE2, Frederic BONELL2, Juan F. SIERRA2, Jo CUPPENS2, Sergio O. VALENZUELA2,3 and Joris VAN DE VONDEL1
1 INPAC - Institute for Nanoscale Physics and Chemistry, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, B-3001 Leuven, Belgium
2 Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona...
The photodetachment of the negative ion of oxygen, although a seemingly simple process, is the subject of a long lasting discrepancy between theory and experiment. On the experimental side, the reference values for the photodetachment cross section are those of Smith and Branscomb et al. [1, 2], which have been widely used to put other relative measurements on an absolute scale. On the...
The first technological SDHCAL prototype having been successfully tested, a new phase of R&D, to validate completely the SDHCAL option for the International Linear Detector (ILD) project of the ILC, has started with the conception and the realization of a new prototype. The new one is intended to host few but large active layers of the future SDHCAL. The new active layers, made of GRPC with...
Interstellar dust absorbs and scatters nearly half of the starlight in the Universe, heavily influencing our view on galaxies. Furthermore, it plays a crucial role in several astrophysical processes. A full understanding of the dust properties and the interplay between dust and starlight is essential to probe the current and past star formation activity and to constrain the cosmic star...
Atomic layer deposition (ALD) is a thin film deposition technique in which the growing film is alternately exposed to typically a chemical precursor and a gas (reactant), each reacting with the surface in a self-limited way. This results in the sequential deposition of mono or sub-monolayers of material and enables the deposition of thin films with precise thickness control and excellent...
We address the state-of-the-art and prospects of the study of three-dimensional intrinsic structure of the nucleon, one of the hot topics in modern high-energy hadron physics. We give an overview of the relevant experiments at current and planned facilities and discuss the most urgent issues in the theory of string interaction - Quantum Chromodynamics - related to the 3D-imaging of the nucleon.
Turbulence is the physical phenomenon responsible for the cascade of energy from large scales, where energy is injected, to small scales, where the energy can eventually be dissipated. Turbulence is ubiquitous in space plasmas and its features in the different regions of the heliosphere (like solar wind, magnetosphere, solar corona ...), along with the mechanisms at small scale responsible for...
After the upgrades of the Large Hadron Collider (LHC) planned for the second and the third Long Shutdown (LS), the LHC luminosity will reach values up to 2×10^34cm−2s−1 and 5×10^34cm−2 s−1 respectively. Such conditions will deeply affect the performance of the CMS muon system, especially in the very forward region, due to the harsh expected background environment and the reduced magnetic...
In proton therapy, proton beams with energies up to typically 230 MeV are used to treat cancerous tumours very efficiently while sparing surrounding healthy tissues as much as possible. Due to nuclear interactions of the proton beams with matter, mainly inside the cyclotron, the beam line, the treatment nozzle and the patient, secondary neutrons with energies up to 230 MeV are unfortunately...
Vanadium dioxide (VO2) is a material that shows an insulator to metal transition (IMT) near room temperature. This property can be exploited for applications in field effect devices, electro-optical switches and nonlinear circuit components. We have prepared VO2 thin films on silicon wafers with a native oxide by combining a low temperature MBE growth with an ex-situ annealing at high...
Vortices and vortex arrays in superfluid atomic Fermi gases in the BCS-BEC crossover are investigated within the finite temperature effective field theory (EFT) [1-4] for a macroscopic wave function representing the field of condensed pairs, analogous to the Ginzburg-Landau theory for superconductors. Here, we have established how rotation modifies this effective field theory, by rederiving it...
YAGG:Cr3+ luminescence : influence of synthesis on luminescent properties
J.H. Bouman 1, M.Tiberi 2, O.Q. De Clercq 1, K. Korthout1, P.F. Smet 1 and D. Poelman 1
1 Lumilab, Dept. Solid State Sciences, Ghent University, Ghent, Belgium
2 Nanomaterials and Interfaces Group (NIG), Chemistry Dept., University of Milan, Milan, Italy
Synthetic Yttrium Aluminium Garnet...
We theoretically explore the dynamic hysteresis behavior of a driven-dissipative photonic resonator with a Kerr-type nonlinearity [1]. In the regime where the semiclassical approach predicts bistability, the exact steady-state density matrix is well known to be unique and a statistical mixture of two states. A direct consequence is that the full quantum treatment predicts no static hysteresis...
A characteristic property of superfluidity and -conductivity is the presence of quantized vortices in rotating systems. To study the BEC-BCS crossover the two most common methods are the Bogoliubov-De Gennes (BdG) theory and the usage of an effective field theory (EFT). In order to simplify the calculations for single vortices, it is often assumed that the hyperbolic tangent yields a good...
In the quest for new physics beyond the Standard Model, decay channels in leptons or photons are particularly interesting, since they arise in clean final states, allowing quick and well defined strategy of analysis.
Resonances in the dielectron and dimuon decay channels arise in many well established theories beyond the standard model, like grand unified theories (GUT) or models proposing...
Carbon-chain molecules have been detected in many astrophysical environments such as interstellar medium (ISM) and circumstellar envelopes. These molecules can be formed in different processes, such as neutral-neutral, ion-neutral or ion-ion collisions and the demand for accurate molecular data concerning these processes is very strong.
We will present measurements of ion pair dissociation...
The closest large galaxy to our own Milky Way is Andromeda (M31). Its proximity allows observations of superb spatial resolution at all wavelengths. We have combined observations of M31 from Earth and space telescopes, ranging from the ultra-violet to millimeter wavelengths. This wavelength range covers the emission from all kinds of stars in this galaxy, but also the dark shadows caused by...
In this work, we describe a novel tool for monitoring the quality of cell cultures in terms of contamination and genomic stability in real time. The proposed platform, the so-called heat-transfer method (HTM), enables to monitor the heat-transfer resistance at solid-liquid interfaces in real-time.1 Previously, it was shown that it is possible to detect cells in buffer solution in a fast,...
Molecular clouds (MC) are the birthplace of stars. This made them a prime object of interest for many observers. But the gas they are mostly composed of is more often than not, hard to observe directly. As a proxy, we look for the dusts present in these clouds. Even if they represent only a fraction of the mass of the MC (up to 1%), they have a strong radiation field associated to them.
An...
Metal-Organic Frameworks (MOFs) are a versatile class of crystalline materials showing great promise in a wide range of applications (e.g. gas sensing and storage, luminescence, pressure sensors, catalysis, …). In addition, their very structure puts them at several cross-sections: classical solids and molecules, surfaces and bulk,… Furthermore, since they combine properties either intrinsic to...
Thiol self-assembled monolayers (SAMs) are popular due to their utility for various applications. In biosensing platforms SAMs are often used as linkers to tether receptors to biochip surfaces [1]. To get a full understanding of SAM-properties, it is important to study also their formation kinetics and thermal-transport properties. This latter point was not addressed before. However, it is...
Active Galactic Nuclei (AGN) are believed to be among the most promising sources of the ultra-high-energy cosmic ray flux. A hadronic component which is accelerated in the high energy environment of an AGN immediately implies the production of high-energy neutrinos. Nevertheless, no clear correlation between AGN and the high-energy cosmic-neutrino flux obtained by IceCube has been found...
The Lieb-Robinson bound has been a milestone in our understanding of the nonequilibrium dynamics of nonrelativistic short-range interacting quantum systems. In essence it states that the effect of a perturbation at a point A cannot be felt at another point B until a time t=r/v, with r the distance between A and B and v a characteristic velocity in the system. Even though causality is not...
Recently, superconductivity in strontium titanate and at the SrTiO3-LaAlO3 interface became a subject of renewed interest because of specific properties of SrTiO3. The superconducting phase transition in these systems occurs at very low temperatures combined with low carrier densities. Strontium titanate is a strongly polar crystal where the Fröhlich electron – LO-phonon interaction dominates...
Important features of physical systems; non-perturbative phenomena, cannot be captured by the most wildly used tool in physics: perturbation theory. Perturbation theory is indeed inherently not complete answer. In QCD for example, the growing number of diagrams implies that perturbation theory does not give a finite result to physical quantities or cannot explain the appearance of a mass...
Unraveling the immense complexity of the human brain requires the ability to selectively interfere and record neural activity. ‘Optogenetics’ describes a variety of techniques for specifically controlling neural activity with light, using light sensitive membrane proteins (opsins).1 Given the significant advantages of nonlinear optics, activating opsins by two-photon absorbance is already an...
The current leading model for cosmology is the ΛCDM model, which assumes a Universe filled with Cold Dark Matter (CDM), and a dark energy component (Λ). The model succesfully predicts the non-linear growth of cosmic structures from the initial density perturbations observed in the Cosmic Microwave Background, to the large scale web of galaxies in the present-day Universe. The ΛCDM predictions...
Colloidal quantum dots are nanometer sized semiconductor crystalllites obtained by solution-based synthesis. They exhibit unique optical and electronic properties that depend on their size, shape and composition. In combination with their suitability for solution processing, many applications are found for these novel materials, ranging from lasing, lighting, photovoltaic devices to...
*Mirko Cormann¹² and Yves Caudano¹²
¹Research Centre in Physics of Matter and Radiation (PMR) ²Namur Center for Complex Systems (NaXyS) University of Namur, rue de Bruxelles 61, Namur, Belgium*
In the last decade, there has been considerable advancement in the study of weak quantum measurements. The experimental observations resulting from weak quantum measurements of pre- and...
When one observes the phenomena in our universe, one notices that the Standard Model (SM) fails to explain several outstanding problems, such as dark matter or dark energy. These shortcomings can be addressed by new physics extensions including new particles and symmetries at higher energy scales. At present, the hope is that unambiguous signals for such new physics will be discovered in the...
We show how to formulate linear thermodynamics for periodic driving including small scale systems. In particular, we derive generalized Onsager-Casimir relations.
We will show the results of two large parametric climate state studies for tidally locked terrestrial planets around M dwarf stars. We investigated for an Earth-like atmosphere and thermal forcing, 3D climate states for rocky planets with sizes between 1-2 Earth radii, orbital periods between 1-100 days, and also for different surface friction scenarios. We identified distinct climate state...
Since the beginning of the 21st century, a novel approach to design alloys with promising properties has been introduced [1]. High-Entropy Alloys (HEAs) are composed of five or more principal elements in equimolar ratios. The high mixing entropy significantly reduces the Gibbs free energy of the solid solution, hence single-phase multi-component solid solutions are thermodynamically stable,...
Surface engineering of micro- and nanoparticles is of great importance in fields such as catalysis, energy, sensing and additive manufacturing. For many of these applications particles are required with different bulk and surface properties. A popular technique to achieve this is to coat the particle surface with a nanometer thick layer. Atomic layer deposition (ALD) is known as a reliable...
Norton's dome is an example of indeterminism in Newtonian physics, based on a differential equation involving a non-Lipschitz continuous function [1]. It involves a gravitational field, in which a mass is placed with velocity zero at the apex of a dome (x=0,v=0), which has the following shape:
y(x)=−2/3(1−(1−3/2|x|)2/3)3/2.
Besides the trivial, singular solution, r(t)=0 (where r is the arc...
The study of fission fragment de-excitation is important for both nuclear applications and fundamental nuclear physics. For modelling innovative nuclear reactor (GEN-IV) cores, a better understanding of the released heat during fission of the major isotopes (235U,239Pu) is crucial. Present knowledge on the released heat states that around 10% of all energy released in fission comes from...
