@article{BieniekSadeckaSzulakowskaetal.2022,
  author    = {Bieniek, Maciej and Sadecka, Katarzyna and Szulakowska, Ludmiła and Hawrylak, Paweł},
  title     = {Theory of excitons in atomically thin semiconductors: tight-binding approach},
  series = {Nanomaterials},
  volume    = {12},
  journal   = {Nanomaterials},
  number    = {9},
  issn      = {2079-4991},
  doi       = {10.3390/nano12091582},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-275243},
  year      = {2022},
  abstract  = {Atomically thin semiconductors from the transition metal dichalcogenide family are materials in which the optical response is dominated by strongly bound excitonic complexes. Here, we present a theory of excitons in two-dimensional semiconductors using a tight-binding model of the electronic structure. In the first part, we review extensive literature on 2D van der Waals materials, with particular focus on their optical response from both experimental and theoretical points of view. In the second part, we discuss our ab initio calculations of the electronic structure of MoS\(_2\), representative of a wide class of materials, and review our minimal tight-binding model, which reproduces low-energy physics around the Fermi level and, at the same time, allows for the understanding of their electronic structure. Next, we describe how electron-hole pair excitations from the mean-field-level ground state are constructed. The electron-electron interactions mix the electron-hole pair excitations, resulting in excitonic wave functions and energies obtained by solving the Bethe-Salpeter equation. This is enabled by the efficient computation of the Coulomb matrix elements optimized for two-dimensional crystals. Next, we discuss non-local screening in various geometries usually used in experiments. We conclude with a discussion of the fine structure and excited excitonic spectra. In particular, we discuss the effect of band nesting on the exciton fine structure; Coulomb interactions; and the topology of the wave functions, screening and dielectric environment. Finally, we follow by adding another layer and discuss excitons in heterostructures built from two-dimensional semiconductors.},
  language  = {en}
}
@article{TuanScharfŽutičetal.2017,
  author    = {Tuan, Dinh Van and Scharf, Benedikt and Žutič, Igor and Dery, Hanan},
  title     = {Marrying excitons and plasmons in monolayer transition-metal dichalcogenides},
  series = {Physical Review X},
  volume    = {7},
  journal   = {Physical Review X},
  number    = {4},
  doi       = {10.1103/PhysRevX.7.041040},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173030},
  year      = {2017},
  abstract  = {Just as photons are the quanta of light, plasmons are the quanta of orchestrated charge-density oscillations in conducting media. Plasmon phenomena in normal metals, superconductors, and doped semiconductors are often driven by long-wavelength Coulomb interactions. However, in crystals whose Fermi surface is comprised of disconnected pockets in the Brillouin zone, collective electron excitations can also attain a shortwave component when electrons transition between these pockets. In this work, we show that the band structure of monolayer transition-metal dichalcogenides gives rise to an intriguing mechanism through which shortwave plasmons are paired up with excitons. The coupling elucidates the origin for the optical sideband that is observed repeatedly in monolayers of WSe\(_2\) and WS\(_2\) but not understood. The theory makes it clear why exciton-plasmon coupling has the right conditions to manifest itself distinctly only in the optical spectra of electron-doped tungsten-based monolayers.},
  language  = {en}
}
@article{BrueningWehnerHausneretal.2016,
  author    = {Br{\"u}ning, Christoph and Wehner, Johannes and Hausner, Julian and Wenzel, Michael and Engel, Volker},
  title     = {Exciton dynamics in perturbed vibronic molecular aggregates},
  series = {Structural Dynamics},
  volume    = {3},
  journal   = {Structural Dynamics},
  doi       = {10.1063/1.4936127},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-126085},
  pages     = {043201},
  year      = {2016},
  abstract  = {A site specific perturbation of a photo-excited molecular aggregate can lead to a localization of excitonic energy. We investigate this localization dynamics for laser-prepared excited states. Changing the parameters of the electric field significantly influences the exciton localization which offers the possibility for a selective control of this process. This is demonstrated for aggregates possessing a single vibrational degree of freedom per monomer unit. It is shown that the effects identified for the molecular dimer can be generalized to larger aggregates with a high density of vibronic states.},
  language  = {en}
}
@article{TempelVeitAssmannetal.2012,
  author    = {Tempel, Jean-Sebastian and Veit, Tempel and Assmann, Marc and Kreilkamp, Lars Erik and H{\"o}fling, Sven and Kamp, Martin and Forchel, Alfred and Bayer, Manfred},
  title     = {Temperature dependence of pulsed polariton lasing in a GaAs microcavity},
  series = {New Journal of Physics},
  volume    = {14},
  journal   = {New Journal of Physics},
  number    = {083014},
  doi       = {10.1088/1367-2630/14/8/083014},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-134022},
  year      = {2012},
  abstract  = {The second-order correlation function g\(^2\)(\(\tau\) = 0), input-output curves and pulse duration of the emission from a microcavity exciton-polariton system subsequent to picosecond-pulsed excitation are measured for different temperatures. At low temperatures a two-threshold behaviour emerges, which has been attributed to the onset of polariton lasing and conventional lasing at the first and the second threshold, respectively. We observe that polariton lasing is stable up to temperatures comparable with the exciton binding energy. At higher temperatures a single threshold displays the direct transition from thermal emission to photon lasing.},
  language  = {en}
}