Calibration of thickness-dependent k-factors for germanium X-ray lines to improve energy-dispersive X-ray spectroscopy of SiGe layers in analytical transmission electron microscopy

We show that the accuracy of energy-dispersive X-ray spectroscopy can be improved by analysing and comparing multiple lines from the same element. For each line, an effective k-factor can be defined that varies as a function of the intensity ratio of multiple lines (e.g. K/L) from the same element. This basically performs an internal self-consistency check in the quantification using differently absorbed X-ray lines, which is in principle equivalent to an absorption correction as a function of specimen thickness but has the practical advantage that the specimen thickness itself does not actually need to be measured

The rise and fall of patterns in driven-dissipative Rydberg polaritons

Spatial structures commonly emerge in interacting nonlinear systems. In this study, we focus on the out-of-equilibrium dynamics of the recently-established platform of Rydberg exciton-polaritons, fueled by their characteristic long-range non-local interactions, in the presence of an external drive and dissipation. Our work elucidates how modulational instability sets off spontaneous density pattern formations in a Rydberg polariton system with characteristic scales in the micron range. Under conditions of an unstable flattop state, we track the evolution of the polariton ensemble, showing the emergence of meta-stable patterns and their collapse in the long-time limit. We trace this phenomenon back to the destructive interference between the polariton state and the pump in a driven ensemble. Finally, we map out conditions that allow stable patterns to form under incoherent pumping. These findings provide new opportunities for exploring the emerging field of long-range interacting gases through Rydberg exciton-polaritons.Comment: 6 pages and 4 figure

Quantum bit detector

We propose and analyze an experimental scheme of quantum nondemolition detection of monophotonic and vacuum states in a superconductive toroidal cavity by means of Rydberg atoms.Comment: 4 pages, 3 figure

Optimal Tableaux Method for Constructive Satisfiability Testing and Model Synthesis in the Alternating-time Temporal Logic ATL+

We develop a sound, complete and practically implementable tableaux-based decision method for constructive satisfiability testing and model synthesis in the fragment ATL+ of the full Alternating time temporal logic ATL*. The method extends in an essential way a previously developed tableaux-based decision method for ATL and works in 2EXPTIME, which is the optimal worst case complexity of the satisfiability problem for ATL+ . We also discuss how suitable parametrizations and syntactic restrictions on the class of input ATL+ formulae can reduce the complexity of the satisfiability problem.Comment: 45 page

A condition on delay for differential equations with discrete state-dependent delay

Parabolic differential equations with discrete state-dependent delay are studied. The approach, based on an additional condition on the delay function introduced in [A.V. Rezounenko, Differential equations with discrete state-dependent delay: uniqueness and well-posedness in the space of continuous functions, Nonlinear Analysis: Theory, Methods and Applications, 70 (11) (2009), 3978-3986] is developed. We propose and study a state-dependent analogue of the condition which is sufficient for the well-posedness of the corresponding initial value problem on the whole space of continuous functions $C$. The dynamical system is constructed in $C$ and the existence of a compact global attractor is proved

Automated background subtraction technique for electron energy-loss spectroscopy and application to semiconductor heterostructures

Electron energy-loss spectroscopy (EELS) has become a stan-dard tool for identification and sometimes also quantificationof elements in materials science. This is important for un-derstanding the chemical and/or structural composition ofprocessed materials. In EELS, the background is often mod-elled using an inverse power-law function. Core-loss ioniza-tion edges are superimposed on top of the dominating back-ground, making it difficult to quantify their intensities. Theinverse power-law has to be modelled for each pre-edge regionof the ionization edges in the spectrum individually ratherthan for the entire spectrum. To achieve this, the prerequisiteis that one knows all core losses possibly present. The aim ofthis study is to automatically detect core-loss edges, model thebackground and extract quantitative elemental maps and pro-files of EELS, based on several EELS spectrum images (EELS SI)without any prior knowledge of the material. The algorithmprovides elemental maps and concentration profiles by makingsmart decisions in selecting pre-edge regions and integrationranges. The results of the quantification for a semiconduc-tor thin film heterostructure show high chemical sensitivity,reasonable group III/V intensity ratios but also quantificationissues when narrow integration windows are used withoutdeconvolution

Generation of a superposition of multiple mesoscopic states of radiation in a resonant cavity

Using resonant interaction between atoms and the field in a high quality cavity, we show how to generate a superposition of many mesoscopic states of the field. We study the quasi-probability distributions and demonstrate the nonclassicality of the superposition in terms of the zeroes of the Q-function as well as the negativity of the Wigner function. We discuss the decoherence of the generated superposition state. We propose homodyne techniques of the type developed by Auffeves et al [Phys. Rev. Lett. 91, 230405 (2003)] to monitor the superposition of many mesoscopic states.Comment: submitted to Phys. Rev.