Research Topics

Soft Quasicrystals:

  • Additional degrees of freedom in quasicrystals: Phasons
  • Phonons are well-known modes in periodic crystals. In quasicrysrtals, which are aperiodic, additional degrees of freedom (correlated rearrangements termed phasons) occur and change their properties.
  • M. Martinsons and M. Schmiedeberg in cooperation with S.C. Kapfer (FAU), J. Roth (Stuttgart), and H. Stark (TU Berlin)
  • Selected Publication: J.A. Kromer et al., PRL 108, 218301 (2012)
  • Supported within the Emmy-Noether-Program of the DFG (Schm 2657/2).
  • Light-induced colloidal quasicrystals
  • By employing the interference patterns of laser beams, a large varity of colloidal quasicrystals can be obtained and studied.
  • M. Schmiedeberg in cooperation with the groups of C. Bechinger (Stuttgart), H. Stark (TU Berlin), and J. Roth (Stuttgart)
  • Selected Publications: F. Rühle et al., EPJE 38, 54 (2015); M. S. et al., EPJE 32, 25 (2010); J. Mikhael et al., PNAS 107, 7214 (2010)
  • Supported within the Emmy-Noether-Program of the DFG (Schm 2657/2).
  • Intrinsic quasicrystals: Stability, growth, defects, and melting
  • We investigate properties of intrinsic colloidal quasicrystals using a phase field crystal model or simulations.
  • M. Martinsons, B. Decker, K. Lenk, and M. Schmiedeberg in cooperation with C.V. Achim, H. Löwen (Düsseldorf), and E.C. Oğuz (Tel Aviv)
  • Selected Publication:
    C.V. Achim et al., PRL 112, 255501 (2014).
  • Photonic and quantum quasicrystals, aperiodic Lorentz gases
  • We are interested in the photonic as well as quantum properties of quasicrystals. Furthermore, we explore the different types of trajectories in quasicrystalline Lorentz gases.
  • Y. Kuang, A. Ibraimi, and M. Schmiedeberg in cooperation with the group of K.P. Schmidt (FAU), R.A. Solórzano Kraemer and D.P. Sanders (Mexico City)
  • Selected Publication: Kraemer et al., Phys. Rev. E 92, 052131 (2015).

Jamming, glassy dynamics, and gels:

  • Structure and glassy dynamics close to a wall
  • Due to the broken anisotropy, studies of a hard sphere system close to a wall reveal interesting insights to cage breaking and glassy dynamics.
  • M. Schmiedeberg in cooperation with A. Härtel (Mainz) and R.A. Solórzano Kraemer (Mexico City)
  • Selected Publication:
    A. Härtel et al., Phys. Rev. E 92, 042310 (2015)
  • Supported within the Emmy-Noether-Program of the DFG (Schm 2657/2).
  • Random Organization and Jamming
  • The random organization transition as well as the jamming transition can be studied by employing similar protocols within a unified model systems. We are especially interested to study mixtures of these two protocols.
  • M. Maiti, S. Ruß, and M. Schmiedeberg
  • Selected Publication:
    L. Milz et al., Phys. Rev. E 88, 062308 (2013)
  • Supported by a grant of the DFG (Schm 2657/3).
  • Gel formation
  • The slowdown of dynamics during gelation in colloid-polymer mixtures is attended by the formation of directed chains of colloids. This structural transition corresponds to a directed percolation transition.
  • M. Schmiedeberg in cooperation with the group of S.U. Egelhaaf (Düsseldorf)
  • Selected Publication: M. Kohl, R.F. Capellmann, M. Laurati, S.U. Egelhaaf, and M. Schmiedeberg, Nature Comm. 7, 11817 (2016)
  • Glassy dynamics of soft sphere systems
  • While for small overlaps the dynamics of soft repulsive spheres can be mapped onto the hard sphere behavior, large overlaps lead to multiple glass transitions and attractions to even more complex behavior.
  • M. Schmiedeberg in cooperation with the group of A.J. Liu (Philadelphia)
  • Selected Publications: M.S., PR E 87, 052310 (2013); M.S. et al., EPL 96, 36010 (2011); T.K. Haxton et al., PR E 83, 031503 (2011)

Complex colloidal structures:

  • Colloidal particles on incommensurate surfaces
  • Ordering, growth, and complex structures on incommensurate substrates.
  • A. Mijailović and M. Schmiedeberg in cooperation with the group of H. Löwen (Düsseldorf)
  • Selected Publications: T. Neuhaus et al., EPJ ST 223, 373 (2014);
    T. Neuhaus et al., PRL. 110, 118301 (2013)
  • Supported within the Emmy-Noether-Program (Schm 2657/2) and the Priority Program SPP 1296 of the DFG.
  • Phases in colloid-polymer mixtures
  • We determine the complex phase behavior of charged colloidal particles that are surrounded by polymers. The resulting depletion attractions lead to a competition of different characteristic interaction length scales.
  • A. Mijailović and M. Schmiedeberg in cooperation with E.C. Oğuz (Tel Aviv)
  • Complex structures obtained with patchy colloids
  • We are interested how preferred binding angles in the case of patchy colloids influence the resulting self-assembled structures. A phase field crystal model is developed for a theoretical description.
  • B. Decker and M. Schmiedeberg
  • Supported by a grant of the DFG (Schm 2657/4).

Normal and Anomalous Diffusion:

  • Browian particle on a rough surface
  • Intermediate and asymptotic regimes of motion of a colloidal particle in a one-dimensional random laser potential.
  • M. Schmiedeberg in cooperation with the group of S.U. Egelhaaf (Düsseldorf)
  • Publications:
    R.D.L. Hanes et al., Phys. Rev. E 88, 062133 (2013);
    R.D.L. Hanes et al., Soft Matter, 8, 2714 (2012)
  • Continuous-Time Random Walks
  • We study and compare different Lévy-Walk and Lévy-Flight models.
  • M. Schmiedeberg in cooperation with the group of V.Yu. Zaburdaev (Dresden)
  • Publications:
    D. Froemberg et al., Phys. Rev. E 91, 022131 (2015);
    M. Schmiedeberg et al., J. Stat. Mech. P12020 (2009);
    V.Yu. Zaburdaev et al., Phys. Rev. E 78, 011119 (2008)

Biophysics:

  • Motility of bacteria
  • Twitching motility of Neisseria gonorrhoeae.
  • M. Schmiedeberg in cooperation with V.Yu. Zaburdaev (Dresden) and other coworkers
  • Publication:
    V.Yu. Zaburdaev et al., Biophysical Journal 107, 1523 (2014)
  • Phase field crystal models for biological systems
  • We are interested in pattern formation processes in systems consisting of living "particles". We develop and study phase field crystal models for their description.
  • D. Geyer and M. Schmiedeberg

Complete list of publications of M. Schmiedeberg: .