Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Abteilungen OPUS4-43983 misc Palyulin, Vladimir V; Blackburn, George; Lomholt, Michael A; Watkins, Nicholas W; Metzler, Ralf; Klages, Rainer; Chechkin, Aleksei V. First passage and first hitting times of Lévy flights and Lévy walks For both Lévy flight and Lévy walk search processes we analyse the full distribution of first-passage and first-hitting (or first-arrival) times. These are, respectively, the times when the particle moves across a point at some given distance from its initial position for the first time, or when it lands at a given point for the first time. For Lévy motions with their propensity for long relocation events and thus the possibility to jump across a given point in space without actually hitting it ('leapovers'), these two definitions lead to significantly different results. We study the first-passage and first-hitting time distributions as functions of the Lévy stable index, highlighting the different behaviour for the cases when the first absolute moment of the jump length distribution is finite or infinite. In particular we examine the limits of short and long times. Our results will find their application in the mathematical modelling of random search processes as well as computer algorithms. 2019 25 Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe 785 urn:nbn:de:kobv:517-opus4-439832 10.25932/publishup-43983 Institut für Physik und Astronomie OPUS4-43982 Wissenschaftlicher Artikel Palyulin, Vladimir V; Blackburn, George; Lomholt, Michael A; Watkins, Nicholas W; Metzler, Ralf; Klages, Rainer; Chechkin, Aleksei V. First passage and first hitting times of Lévy flights and Lévy walks For both Lévy flight and Lévy walk search processes we analyse the full distribution of first-passage and first-hitting (or first-arrival) times. These are, respectively, the times when the particle moves across a point at some given distance from its initial position for the first time, or when it lands at a given point for the first time. For Lévy motions with their propensity for long relocation events and thus the possibility to jump across a given point in space without actually hitting it ('leapovers'), these two definitions lead to significantly different results. We study the first-passage and first-hitting time distributions as functions of the Lévy stable index, highlighting the different behaviour for the cases when the first absolute moment of the jump length distribution is finite or infinite. In particular we examine the limits of short and long times. Our results will find their application in the mathematical modelling of random search processes as well as computer algorithms. Bad Honnef Dt. Physikalische Ges. 2019 24 New Journal of Physics 21 10.1088/1367-2630/ab41bb Institut für Physik und Astronomie OPUS4-57168 Wissenschaftlicher Artikel Kurilovich, Aleksandr A.; Mantsevich, Vladimir; Stevenson, Keith J.; Chechkin, Aleksei V.; Palyulin, V. V. Complex diffusion-based kinetics of photoluminescence in semiconductor nanoplatelets We present a diffusion-based simulation and theoretical models for explanation of the photoluminescence (PL) emission intensity in semiconductor nanoplatelets. It is shown that the shape of the PL intensity curves can be reproduced by the interplay of recombination, diffusion and trapping of excitons. The emission intensity at short times is purely exponential and is defined by recombination. At long times, it is governed by the release of excitons from surface traps and is characterized by a power-law tail. We show that the crossover from one limit to another is controlled by diffusion properties. This intermediate region exhibits a rich behaviour depending on the value of diffusivity. The proposed approach reproduces all the features of experimental curves measured for different nanoplatelet systems. Cambridge Royal Society of Chemistry 2020 11 Physical chemistry, chemical physics : a journal of European Chemical Societies 22 42 24686 24696 10.1039/d0cp03744c Institut für Physik und Astronomie