@misc{PavlenkoSanderMitzscherlingetal.2016,
  author    = {Pavlenko, Elena S. and Sander, Mathias and Mitzscherling, Steffen and Pudell, Jan-Etienne and Zamponi, Flavio and R{\"o}ssle, Matthias and Bojahr, Andre and Bargheer, Matias},
  title     = {Azobenzene - functionalized polyelectrolyte nanolayers as ultrafast optoacoustic transducers},
  volume    = {8},
  doi       = {10.1039/C6NR01448H},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-101996},
  pages     = {13297 -- 13302},
  year      = {2016},
  abstract  = {We introduce azobenzene-functionalized polyelectrolyte multilayers as efficient, inexpensive optoacoustic transducers for hyper-sound strain waves in the GHz range. By picosecond transient reflectivity measurements we study the creation of nanoscale strain waves, their reflection from interfaces, damping by scattering from nanoparticles and propagation in soft and hard adjacent materials like polymer layers, quartz and mica. The amplitude of the generated strain ε ∼ 5 × 10-4 is calibrated by ultrafast X-ray diffraction.},
  language  = {en}
}
@misc{GarciaBenitoQuartiQuelozetal.2020,
  author    = {Garc{\´i}a-Benito, In{\´e}s and Quarti, Claudio and Queloz, Valentin I. E. and Hofstetter, Yvonne J. and Becker-Koch, David and Caprioglio, Pietro and Neher, Dieter and Orlandi, Simonetta and Cavazzini, Marco and Pozzi, Gianluca and Even, Jacky and Nazeeruddin, Mohammad Khaja and Vaynzof, Yana and Grancini, Giulia},
  title     = {Fluorination of organic spacer impacts on the structural and optical response of 2D perovskites},
  series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-51242},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-512420},
  pages     = {13},
  year      = {2020},
  abstract  = {Low-dimensional hybrid perovskites have triggered significant research interest due to their intrinsically tunable optoelectronic properties and technologically relevant material stability. In particular, the role of the organic spacer on the inherent structural and optical features in two-dimensional (2D) perovskites is paramount for material optimization. To obtain a deeper understanding of the relationship between spacers and the corresponding 2D perovskite film properties, we explore the influence of the partial substitution of hydrogen atoms by fluorine in an alkylammonium organic cation, resulting in (Lc)(2)PbI4 and (Lf)(2)PbI4 2D perovskites, respectively. Consequently, optical analysis reveals a clear 0.2 eV blue-shift in the excitonic position at room temperature. This result can be mainly attributed to a band gap opening, with negligible effects on the exciton binding energy. According to Density Functional Theory (DFT) calculations, the band gap increases due to a larger distortion of the structure that decreases the atomic overlap of the wavefunctions and correspondingly bandwidth of the valence and conduction bands. In addition, fluorination impacts the structural rigidity of the 2D perovskite, resulting in a stable structure at room temperature and the absence of phase transitions at a low temperature, in contrast to the widely reported polymorphism in some non-fluorinated materials that exhibit such a phase transition. This indicates that a small perturbation in the material structure can strongly influence the overall structural stability and related phase transition of 2D perovskites, making them more robust to any phase change. This work provides key information on how the fluorine content in organic spacer influence the structural distortion of 2D perovskites and their optical properties which possess remarkable importance for future optoelectronic applications, for instance in the field of light-emitting devices or sensors.},
  language  = {en}
}
@misc{ReindlFinchSchaffenrothetal.2018,
  author    = {Reindl, Nicole and Finch, Nicolle L. and Schaffenroth, Veronika and Barstow, Martin A. and Casewell, Sarah L. and Geier, Stephan and Bertolami Miller, Marcelo Miguel and Taubenberger, Stefan},
  title     = {Revealing the true nature of Hen2-428},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1129},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-45970},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-459703},
  pages     = {9},
  year      = {2018},
  abstract  = {The nucleus of Hen 2-428 is a short orbital period (4.2 h) spectroscopic binary, whose status as potential supernovae type Ia progenitor has raised some controversy in the literature. We present preliminary results of a thorough analysis of this interesting system, which combines quantitative non-local thermodynamic (non-LTE) equilibrium spectral modelling, radial velocity analysis, multi-band light curve fitting, and state-of-the art stellar evolutionary calculations. Importantly, we find that the dynamical system mass that is derived by using all available He II lines does not exceed the Chandrasekhar mass limit. Furthermore, the individual masses of the two central stars are too small to lead to an SN Ia in case of a dynamical explosion during the merger process.},
  language  = {en}
}
@misc{vonReppertPuddellKocetal.2016,
  author    = {von Reppert, Alexander and Puddell, J. and Koc, A. and Reinhardt, M. and Leitenberger, Wolfram and Dumesnil, K. and Zamponi, Flavio and Bargheer, Matias},
  title     = {Persistent nonequilibrium dynamics of the thermal energies in the spin and phonon systems of an antiferromagnet},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-98710},
  pages     = {11},
  year      = {2016},
  abstract  = {We present a temperature and fluence dependent Ultrafast X-Ray Diffraction study of a laser-heated antiferromagnetic dysprosium thin film. The loss of antiferromagnetic order is evidenced by a pronounced lattice contraction. We devise a method to determine the energy flow between the phonon and spin system from calibrated Bragg peak positions in thermal equilibrium. Reestablishing the magnetic order is much slower than the cooling of the lattice, especially around the N{\´e}el temperature. Despite the pronounced magnetostriction, the transfer of energy from the spin system to the phonons in Dy is slow after the spin-order is lost.},
  language  = {en}
}
@misc{MatternPudellDumesniletal.2023,
  author    = {Mattern, Maximilian and Pudell, Jan-Etienne and Dumesnil, Karine and von Reppert, Alexander and Bargheer, Matias},
  title     = {Towards shaping picosecond strain pulses via magnetostrictive transducers},
  series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1321},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-58886},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-588868},
  pages     = {7},
  year      = {2023},
  abstract  = {Using time-resolved x-ray diffraction, we demonstrate the manipulation of the picosecond strain response of a metallic heterostructure consisting of a dysprosium (Dy) transducer and a niobium (Nb) detection layer by an external magnetic field. We utilize the first-order ferromagnetic-antiferromagnetic phase transition of the Dy layer, which provides an additional large contractive stress upon laser excitation compared to its zerofield response. This enhances the laser-induced contraction of the transducer and changes the shape of the picosecond strain pulses driven in Dy and detected within the buried Nb layer. Based on our experiment with rare-earth metals we discuss required properties for functional transducers, which may allow for novel field-control of the emitted picosecond strain pulses.},
  language  = {en}
}
@misc{ZeuschnerMatternPudelletal.2021,
  author    = {Zeuschner, Steffen Peer and Mattern, Maximilian and Pudell, Jan-Etienne and von Reppert, Alexander and R{\"o}ssle, M. and Leitenberger, Wolfram and Schwarzkopf, J. and Boschker, J. E. and Herzog, Marc and Bargheer, Matias},
  title     = {Reciprocal space slicing},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1137},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-49976},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-499761},
  pages     = {13},
  year      = {2021},
  abstract  = {An experimental technique that allows faster assessment of out-of-plane strain dynamics of thin film heterostructures via x-ray diffraction is presented. In contrast to conventional high-speed reciprocal space-mapping setups, our approach reduces the measurement time drastically due to a fixed measurement geometry with a position-sensitive detector. This means that neither the incident (ω) nor the exit (2θ) diffraction angle is scanned during the strain assessment via x-ray diffraction. Shifts of diffraction peaks on the fixed x-ray area detector originate from an out-of-plane strain within the sample. Quantitative strain assessment requires the determination of a factor relating the observed shift to the change in the reciprocal lattice vector. The factor depends only on the widths of the peak along certain directions in reciprocal space, the diffraction angle of the studied reflection, and the resolution of the instrumental setup. We provide a full theoretical explanation and exemplify the concept with picosecond strain dynamics of a thin layer of NbO2.},
  language  = {en}
}
@misc{MitzscherlingCuiKoopmanetal.2015,
  author    = {Mitzscherling, Steffen and Cui, Qianling and Koopman, Wouter-Willem Adriaan and Bargheer, Matias},
  title     = {Dielectric function of two-phase colloid-polymer nanocomposite},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-102695},
  pages     = {29465 -- 29474},
  year      = {2015},
  abstract  = {The plasmon resonance of metal nanoparticles determines their optical response in the visible spectral range. Many details such as the electronic properties of gold near the particle surface and the local environment of the particles influence the spectra. We show how the cheap but highly precise fabrication of composite nanolayers by spin-assisted layer-by-layer deposition of polyelectrolytes can be used to investigate the spectral response of gold nanospheres (GNS) and gold nanorods (GNR) in a self-consistent way, using the established Maxwell-Garnett effective medium (MGEM) theory beyond the limit of homogeneous media. We show that the dielectric function of gold nanoparticles differs from the bulk value and experimentally characterize the shape and the surrounding of the particles thoroughly by SEM, AFM and ellipsometry. Averaging the dielectric functions of the layered surrounding by an appropriate weighting with the electric field intensity yields excellent agreement for the spectra of several nanoparticles and nanorods with various cover-layer thicknesses.},
  language  = {en}
}
@misc{MatternPudellLaskinetal.2021,
  author    = {Mattern, Maximilian and Pudell, Jan-Etienne and Laskin, G. and von Reppert, Alexander and Bargheer, Matias},
  title     = {Analysis of the temperature- and fluence-dependent magnetic stress in laser-excited SrRuO3},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-51571},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-515718},
  pages     = {11},
  year      = {2021},
  abstract  = {We use ultrafast x-ray diffraction to investigate the effect of expansive phononic and contractive magnetic stress driving the picosecond strain response of a metallic perovskite SrRuO3 thin film upon femtosecond laser excitation. We exemplify how the anisotropic bulk equilibrium thermal expansion can be used to predict the response of the thin film to ultrafast deposition of energy. It is key to consider that the laterally homogeneous laser excitation changes the strain response compared to the near-equilibrium thermal expansion because the balanced in-plane stresses suppress the Poisson stress on the picosecond timescale. We find a very large negative Gr{\"u}neisen constant describing the large contractive stress imposed by a small amount of energy in the spin system. The temperature and fluence dependence of the strain response for a double-pulse excitation scheme demonstrates the saturation of the magnetic stress in the high-fluence regime.},
  language  = {en}
}
@misc{LomadzeKopyshevBargheeretal.2017,
  author    = {Lomadze, Nino and Kopyshev, Alexey and Bargheer, Matias and Wollgarten, Markus and Santer, Svetlana},
  title     = {Mass production of polymer nanowires filled with metal nanoparticles},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-402712},
  pages     = {10},
  year      = {2017},
  abstract  = {Despite the ongoing progress in nanotechnology and its applications, the development of strategies for connecting nano-scale systems to micro- or macroscale elements is hampered by the lack of structural components that have both, nano- and macroscale dimensions. The production of nano-scale wires with macroscale length is one of the most interesting challenges here. There are a lot of strategies to fabricate long nanoscopic stripes made of metals, polymers or ceramics but none is suitable for mass production of ordered and dense arrangements of wires at large numbers. In this paper, we report on a technique for producing arrays of ordered, flexible and free-standing polymer nano-wires filled with different types of nano-particles. The process utilizes the strong response of photosensitive polymer brushes to irradiation with UV-interference patterns, resulting in a substantial mass redistribution of the polymer material along with local rupturing of polymer chains. The chains can wind up in wires of nano-scale thickness and a length of up to several centimeters. When dispersing nano-particles within the film, the final arrangement is similar to a core-shell geometry with mainly nano-particles found in the core region and the polymer forming a dielectric jacket.},
  language  = {en}
}
@misc{ThielRomanoKurthsetal.2006,
  author    = {Thiel, Marco and Romano, Maria Carmen and Kurths, J{\"u}rgen and Rolfs, Martin and Kliegl, Reinhold},
  title     = {Generating Surrogates from Recurrences},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-56906},
  year      = {2006},
  abstract  = {In this paper we present an approach to recover the dynamics from recurrences of a system and then generate (multivariate) twin surrogate (TS) trajectories. In contrast to other approaches, such as the linear-like surrogates, this technique produces surrogates which correspond to an independent copy of the underlying system, i. e. they induce a trajectory of the underlying system visiting the attractor in a different way. We show that these surrogates are well suited to test for complex synchronization, which makes it possible to systematically assess the reliability of synchronization analyses. We then apply the TS to study binocular fixational movements and find strong indications that the fixational movements of the left and right eye are phase synchronized. This result indicates that there might be one centre only in the brain that produces the fixational movements in both eyes or a close link between two centres.},
  language  = {en}
}