Controlling the quantum number distribution and yield of Rydberg states via the duration of the laser pulse

We show that the distribution of quantum numbers of Rydberg states does not only depend on the field strength and wavelength of the laser which the atom is exposed to, but that it also changes significantly with the duration of the laser pulse. We provide an intuitive explanation for the underlying mechanism and derive a scaling law for the position of the peak in the quantum number distribution on the pulse duration. The new analytic description for the electron's movement in the superposed laser and Coulomb field (applied in the study of quantum numbers) is then used to explain the decrease of the Rydberg yield with longer pulse durations. This description stands in contrast to the concepts that explained the decrease so far and also reveals that approximations which neglect Coulomb effects during propagation are not sufficient in cases such as this.Comment: 8 pages, 8 figure

Double-electron ionization driven by inhomogeneous fields

Authors may self-archive the author’s accepted manuscript of their articles on their own websites. Authors may also deposit this version of the article in any repository, provided it is only made publicly available 12 months after official publication or later. He/ she may not use the publisher's version (the final article), which is posted on SpringerLink and other Springer websites, for the purpose of self-archiving or deposit. Furthermore, the author may only post his/her version provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be provided by inserting the DOI number of the article in the following sentence: “The final publication is available at Springer via https://link.springer.com/article/10.1007/s00340-017-6672-4"Electron–electron correlation effects play a crucial role in our understanding of sequential (SDI) and non-sequential double ionization (NSDI) mechanisms. Here, we present a theoretical study of NSDI driven by plasmonic-enhanced spatial inhomogeneous fields. By numerically solving the time-dependent Schrödinger equation for a linear reduced model of He and a double-electron time-evolution probability analysis, we provide evidence for enhancement effects in NSDI showing that the double ionization yield at lower laser peak intensities is increased due to the spatial inhomogeneous character of plasmonic-enhanced field. The change in the emission direction of the double-ion as a function of the field inhomogeneity degree demonstrates that plasmonic-enhanced fields could configure a reliable instrument to control the ion emission. Furthermore, our quantum mechanical model, as well as classical trajectory Monte Carlo simulations, show that inhomogeneous fields are as well as a useful tool for splitting the binary and recoil processes in the rescattering scenario.This work was supported by the project ELI-Extreme Light Infrastructure-phase 2 (Project No. CZ.02.1.01/0.0/0.0/ 15_008/0000162) from European Regional Development Fund, Spanish MINECO (National Plan grants FIS2011-30465-C02-01, FOQUS No. FIS2013-46768-P, FISICATEAMO FIS2016-79508-P and Severo Ochoa Excellence Grant No. SEV-2015-0522), the Generalitat de Catalunya (SGR 874 and CERCA/Program) and Fundació Privada Cellex Barcelona. N.S. was supported by the Erasmus Mundus Doctorate Program Europhotonics (Grant No. 159224-1-2009-1-FR-ERA MUNDUS-EMJD). N.S., A.C., and M.L. acknowledge ERC AdG OSYRIS, EU FETPRO QUIC and National Science Centre, Poland—Symfonia Grant 2016/20/W/ST4/00314. A. S. L. acknowledges Max Planck Center for Attosecond Science (MPC-AS). J. A. P.-H. acknowledges to the Spanish Ministerio de Economía y Competitivi- dad (FURIAM Project No. FIS2013-47741-R and PALMA project FIS2016- 81056-R) and Laserlab-Europe (EU-H2020 654148). L.O. acknowledges valuable input from Andre Staudte. The authors thankfully acknowledge the computer resources at MareNostrum, technical expertise and assistance provided by the Barcelona Supercomputing Center and the Red Española de Supercomputación (RES)Peer ReviewedPostprint (author's final draft

Onset and Saturation of Ion Heating by Odd-parity Rotating-magnetic-fields in a Field-reversed Configuration

Heating of figure-8 ions by odd-parity rotating magnetic fields (RMFο) applied to an elongated field-reversed configuration (FRC) is investigated. The largest energy gain occurs at resonances (s ≡ ω(sub)R⁄ω) of the RMFο frequency, ω(sub)R, with the figure-8 orbital frequency, ω, and is proportional to s^2 for s – even resonances and to s for s – odd resonances. The threshold for the transition from regular to stochastic orbits explains both the onset and saturation of heating. The FRC magnetic geometry lowers the threshold for heating below that in the tokamak by an order of magnitude

A model-theoretic interpretation of environmentally-induced superselection

Environmentally-induced superselection or "einselection" has been proposed as an observer-independent mechanism by which apparently classical systems "emerge" from physical interactions between degrees of freedom described completely quantum-mechanically. It is shown that einselection can only generate classical systems if the "environment" is assumed \textit{a priori} to be classical; einselection therefore does not provide an observer-independent mechanism by which classicality can emerge from quantum dynamics. Einselection is then reformulated in terms of positive operator-valued measures (POVMs) acting on a global quantum state. It is shown that this re-formulation enables a natural interpretation of apparently-classical systems as virtual machines that requires no assumptions beyond those of classical computer science.Comment: 15 pages, 1 figure; minor correction

De sensatie van een goed leven bij autisme en een verstandelijke beperking

Problemen in de prikkelverwerking staan een ‘goed leven’ voor mensen met autisme en een verstandelijke beperking vaak behoorlijk in de weg. Daarom startte de unit Toegepast GezondheidsOnderzoek (TGO) van het Universitair Medisch Centrum Groningen-Gezondheidswetenschappen in 2017 het project De Sensatie van een Goed Leven (SGL, zie verder kader 2). Doel van dit project is het ontwikkelen van een aanpak voor een beter leven voor mensen met autisme en een verstandelijke beperking, via een optimale prikkelbalans. Met prikkelbalans bedoelen we dat iemand optimaal in staat is om zintuiglijke prikkels te verwerken, zonder over- of onderprikkeld te raken. In dit artikel beschrijven we de methode van het project, geven we een kort overzicht van de huidige kennis en laten we zien hoe de in dit project ontwikkelde ‘aanpak’ eruitziet en waar je die kunt vinden

De sensatie van een goed leven bij autisme en een verstandelijke beperking

Problemen in de prikkelverwerking staan een ‘goed leven’ voor mensen met autisme en een verstandelijke beperking vaak behoorlijk in de weg. Daarom startte de unit Toegepast GezondheidsOnderzoek (TGO) van het Universitair Medisch Centrum Groningen-Gezondheidswetenschappen in 2017 het project De Sensatie van een Goed Leven (SGL, zie verder kader 2). Doel van dit project is het ontwikkelen van een aanpak voor een beter leven voor mensen met autisme en een verstandelijke beperking, via een optimale prikkelbalans. Met prikkelbalans bedoelen we dat iemand optimaal in staat is om zintuiglijke prikkels te verwerken, zonder over- of onderprikkeld te raken. In dit artikel beschrijven we de methode van het project, geven we een kort overzicht van de huidige kennis en laten we zien hoe de in dit project ontwikkelde ‘aanpak’ eruitziet en waar je die kunt vinden