@article{LiShanRupprechtetal.2022,
  author    = {Li, Donghai and Shan, Hangyong and Rupprecht, Christoph and Knopf, Heiko and Watanabe, Kenji and Taniguchi, Takashi and Qin, Ying and Tongay, Sefaattin and Nuß, Matthias and Schr{\"o}der, Sven and Eilenberger, Falk and H{\"o}fling, Sven and Schneider, Christian and Brixner, Tobias},
  title     = {Hybridized exciton-photon-phonon states in a transition-metal-dichalcogenide van-der-Waals heterostructure microcavity},
  series = {Physical Review Letters},
  journal   = {Physical Review Letters},
  edition   = {accepted version},
  issn      = {1079-7114},
  doi       = {10.1103/PhysRevLett.128.087401},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-351303},
  year      = {2022},
  abstract  = {Excitons in atomically thin transition-metal dichalcogenides (TMDs) have been established as an attractive platform to explore polaritonic physics, owing to their enormous binding energies and giant oscillator strength. Basic spectral features of exciton polaritons in TMD microcavities, thus far, were conventionally explained via two-coupled-oscillator models. This ignores, however, the impact of phonons on the polariton energy structure. Here we establish and quantify the threefold coupling between excitons, cavity photons, and phonons. For this purpose, we employ energy-momentum-resolved photoluminescence and spatially resolved coherent two-dimensional spectroscopy to investigate the spectral properties of a high-quality-factor microcavity with an embedded WSe\(_2\) van-der-Waals heterostructure at room temperature. Our approach reveals a rich multi-branch structure which thus far has not been captured in previous experiments. Simulation of the data reveals hybridized exciton-photon-phonon states, providing new physical insight into the exciton polariton system based on layered TMDs.},
  language  = {en}
}
@unpublished{HuberPresWittmannetal.2019,
  author    = {Huber, Bernhard and Pres, Sebastian and Wittmann, Emanuel and Dietrich, Lysanne and L{\"u}ttig, Julian and Fersch, Daniel and Krauss, Enno and Friedrich, Daniel and Kern, Johannes and Lisinetskii, Victor and Hensen, Matthias and Hecht, Bert and Bratschitsch, Rudolf and Riedle, Eberhard and Brixner, Tobias},
  title     = {Space- and time-resolved UV-to-NIR surface spectroscopy and 2D nanoscopy at 1 MHz repetition rate},
  issn      = {0034-6748},
  doi       = {10.1063/1.5115322},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-191906},
  year      = {2019},
  abstract  = {We describe a setup for time-resolved photoemission electron microscopy (TRPEEM) with aberration correction enabling 3 nm spatial resolution and sub-20 fs temporal resolution. The latter is realized by our development of a widely tunable (215-970 nm) noncollinear optical parametric amplifier (NOPA) at 1 MHz repetition rate. We discuss several exemplary applications. Efficient photoemission from plasmonic Au nanoresonators is investigated with phase-coherent pulse pairs from an actively stabilized interferometer. More complex excitation fields are created with a liquid-crystal-based pulse shaper enabling amplitude and phase shaping of NOPA pulses with spectral components from 600 to 800 nm. With this system we demonstrate spectroscopy within a single plasmonic nanoslit resonator by spectral amplitude shaping and investigate the local field dynamics with coherent two-dimensional (2D) spectroscopy at the nanometer length scale ("2D nanoscopy"). We show that the local response varies across a distance as small as 33 nm in our sample. Further, we report two-color pump-probe experiments using two independent NOPA beamlines. We extract local variations of the excited-state dynamics of a monolayered 2D material (WSe2) that we correlate with low-energy electron microscopy (LEEM) and reflectivity (LEER) measurements. Finally, we demonstrate the in-situ sample preparation capabilities for organic thin films and their characterization via spatially resolved electron diffraction and dark-field LEEM.},
  language  = {en}
}