@article{SarhanKoopmanPudelletal.2019,
  author    = {Sarhan, Radwan Mohamed and Koopman, Wouter-Willem Adriaan and Pudell, Jan-Etienne and Stete, Felix and R{\"o}ssle, Matthias and Herzog, Marc and Schmitt, Clemens Nikolaus Zeno and Liebig, Ferenc and Koetz, Joachim and Bargheer, Matias},
  title     = {Scaling up nanoplasmon catalysis},
  series = {The journal of physical chemistry : C, Nanomaterials and interfaces},
  volume    = {123},
  journal   = {The journal of physical chemistry : C, Nanomaterials and interfaces},
  number    = {14},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1932-7447},
  doi       = {10.1021/acs.jpcc.8b12574},
  pages     = {9352 -- 9357},
  year      = {2019},
  abstract  = {Nanoscale heating by optical excitation of plasmonic nanoparticles offers a new perspective of controlling chemical reactions, where heat is not spatially uniform as in conventional macroscopic heating but strong temperature gradients exist around microscopic hot spots. In nanoplasmonics, metal particles act as a nanosource of light, heat, and energetic electrons driven by resonant excitation of their localized surface plasmon resonance. As an example of the coupling reaction of 4-nitrothiophenol into 4,4′-dimercaptoazobenzene, we show that besides the nanoscopic heat distribution at hot spots, the microscopic distribution of heat dictated by the spot size of the light focus also plays a crucial role in the design of plasmonic nanoreactors. Small sizes of laser spots enable high intensities to drive plasmon-assisted catalysis. This facilitates the observation of such reactions by surface-enhanced Raman scattering, but it challenges attempts to scale nanoplasmonic chemistry up to large areas, where the excess heat must be dissipated by one-dimensional heat transport.},
  language  = {en}
}
@article{SteteSchossauBargheeretal.2018,
  author    = {Stete, Felix and Schossau, Phillip and Bargheer, Matias and Koopman, Wouter-Willem Adriaan},
  title     = {Size-Dependent coupling of Hybrid Core-Shell Nanorods},
  series = {The journal of physical chemistry : C, Nanomaterials and interfaces},
  volume    = {122},
  journal   = {The journal of physical chemistry : C, Nanomaterials and interfaces},
  number    = {31},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1932-7447},
  doi       = {10.1021/acs.jpcc.8b04204},
  pages     = {17976 -- 17982},
  year      = {2018},
  abstract  = {Owing to their ability of concentrating electromagnetic fields to subwavelength mode volumes, plasmonic nanoparticles foster extremely high light-matter coupling strengths reaching far into the strong-coupling regime of light matter interaction. In this article, we present an experimental investigation on the dependence of coupling strength on the geometrical size of the nanoparticle. The coupling strength for differently sized hybrid plasmon-core exciton-shell nanorods was extracted from the typical resonance anticrossing of these systems, obtained by controlled modification of the environment permittivity using layer-by-layer deposition of polyelectrolytes. The observed size dependence of the coupling strength can be explained by a simple model approximating the electromagnetic mode volume by the geometrical volume of the particle. On the basis of this model, the coupling strength for particles of arbitrary size can be predicted, including the particle size necessary to support single-emitter strong coupling.},
  language  = {en}
}
@misc{SteteSchossauKoopmanetal.2018,
  author    = {Stete, Felix and Schossau, Phillip Gerald and Koopman, Wouter-Willem Adriaan and Bargheer, Matias},
  title     = {Size Dependence of the Coupling Strength in Plasmon-Exciton Nanoparticles},
  series = {Quantum Nano-Photonics},
  journal   = {Quantum Nano-Photonics},
  publisher = {Springer},
  address   = {Dordrecht},
  isbn      = {978-94-024-1546-9},
  issn      = {1871-465X},
  doi       = {10.1007/978-94-024-1544-5_26},
  pages     = {381 -- 383},
  year      = {2018},
  abstract  = {The coupling between molecular excitations and nanoparticles leads to promising applications. It is for example used to enhance the optical cross-section of molecules in surface enhanced Raman scattering, Purcell enhancement or plasmon enhanced dye lasers. In a coupled system new resonances emerge resulting from the original plasmon (ωpl) and exciton (ωex) resonances as ω±=12(ωpl+ωex)±14(ωpl-ωex)2+g2---------------√, (1) where g is the coupling parameter. Hence, the new resonances show a separation of Δ = ω+ - ω- from which the coupling strength can be deduced from the minimum distance between the two resonances, Ω = Δ(ω+ = ω-).},
  language  = {en}
}
@misc{SteteKoopmanBargheer2018,
  author    = {Stete, Felix and Koopman, Wouter-Willem Adriaan and Bargheer, Matias},
  title     = {Signatures of strong coupling on nanoparticles},
  series = {Quantum Nano-Photonics},
  journal   = {Quantum Nano-Photonics},
  publisher = {Springer},
  address   = {Dordrecht},
  isbn      = {978-94-024-1546-9},
  issn      = {1871-465X},
  doi       = {10.1007/978-94-024-1544-5_53},
  pages     = {445 -- 447},
  year      = {2018},
  abstract  = {The electromagnetic coupling of molecular excitations to plasmonic nanoparticles offers a promising method to manipulate the light-matter interaction at the nanoscale. Plasmonic nanoparticles foster exceptionally high coupling strengths, due to their capacity to strongly concentrate the light-field to sub-wavelength mode volumes. A particularly interesting coupling regime occurs, if the coupling increases to a level such that the coupling strength surpasses all damping rates in the system. In this so-called strong-coupling regime hybrid light-matter states emerge, which can no more be divided into separate light and matter components. These hybrids unite the features of the original components and possess new resonances whose positions are separated by the Rabi splitting energy h Omega. Detuning the resonance of one of the components leads to an anticrossing of the two arising branches of the new resonances omega(+) and omega(-) with a minimal separation of Omega = omega(+) - omega(-).},
  language  = {en}
}
@article{SteteKoopmanBargheer2017,
  author    = {Stete, Felix and Koopman, Wouter-Willem Adriaan and Bargheer, Matias},
  title     = {Signatures of strong coupling on nanoparticles},
  series = {ACS Photonics},
  volume    = {4},
  journal   = {ACS Photonics},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {2330-4022},
  doi       = {10.1021/acsphotonics.7b00113},
  pages     = {1669 -- 1676},
  year      = {2017},
  abstract  = {In the strong coupling regime, exciton and plasmon excitations are hybridized into combined system excitations. The correct identification of the coupling regime in these systems is currently debated, from both experimental and theoretical perspectives. In this article we show that the extinction spectra may show a large peak splitting, although the energy loss encoded in the absorption spectra clearly rules out the strong coupling regime. We investigate the coupling of J-aggregate excitons to the localized surface plasmon polaritons on gold nanospheres and nanorods by fine-tuning the plasmon resonance via layer-by-layer deposition of polyelectrolytes. While both structures show a characteristic anticrossing in extinction and scattering experiments, the careful assessment of the systems' light absorption reveals that strong coupling of the plasmon to the exciton is not present in the nanosphere system. In a phenomenological model of two classical coupled oscillators, a Fano-like regime causes only the resonance of the light-driven oscillator to split up, while the other one still dissipates energy at its original frequency. Only in the strong-coupling limit do both oscillators split up the frequencies at which they dissipate energy, qualitatively explaining our experimental finding.},
  language  = {en}
}
@article{vonReppertSarhanSteteetal.2016,
  author    = {von Reppert, Alexander and Sarhan, Radwan Mohamed and Stete, Felix and Pudell, Jan-Etienne and Del Fatti, N. and Crut, A. and Koetz, Joachim and Liebig, Ferenc and Prietzel, Claudia Christina and Bargheer, Matias},
  title     = {Watching the Vibration and Cooling of Ultrathin Gold Nanotriangles by Ultrafast X-ray Diffraction},
  series = {The journal of physical chemistry : C, Nanomaterials and interfaces},
  volume    = {120},
  journal   = {The journal of physical chemistry : C, Nanomaterials and interfaces},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1932-7447},
  doi       = {10.1021/acs.jpcc.6b11651},
  pages     = {28894 -- 28899},
  year      = {2016},
  abstract  = {We study the vibrations of ultrathin gold nanotriangles upon optical excitation of the electron gas by ultrafast X-ray diffraction. We quantitatively measure the strain evolution in these highly asymmetric nano-objects, providing a direct estimation of the amplitude and phase of the excited vibrational motion. The maximal strain value is well reproduced by calculations addressing pump absorption by the nanotriangles and their resulting thermal expansion. The amplitude and phase of the out-of-plane vibration mode with 3.6 ps period dominating the observed oscillations are related to two distinct excitation mechanisms. Electronic and phonon pressures impose stresses with different time dependences. The nanosecond relaxation of the expansion yields a direct temperature sensing of the nano-object. The presence of a thin organic molecular layer at the nanotriangle/substrate interfaces drastically reduces the thermal conductance to the substrate.},
  language  = {en}
}