Abstract

- The polaron, as introduced by Landau, referred to the coupling of an electron with the lattice deformation it induces in a polar crystal. At present, the polaron concept has been greatly broadened to various contexts, for example, excitonic and ripplonic polarons, polarons in organic materials, in nanostructures, in quantum gases, and spin-orbit entangled polarons. 

- Traditional theoretical frameworks of polaron physics were restricted on the linear-harmonic approximation for the phonon field and for the electron-phonon interaction. The inclusion of higher-order terms beyond the linear-harmonic approximation can markedly influence the optical response and kinetics of impurities embedded within crystals. In recent years, considerable effort in this direction resulted in the emergence of the concept of an anharmonic polaron. 

- The present minicolloquium is partially focused on spin-orbit entangled anharmonic polarons [1-3], but it is not restricted to these areas. It aims to bring together experts in various aspects of polaron physics in different media (crystals, polymers, quantum gases, surfaces and layered structures) and to highlight recent developments in methodology and applications of the polaron concept.

REFERENCES

[1] S. Ragni, T. Hahn, Z. Zhang, N. Prokof'ev, A. Kuklov, S. N. Klimin, M. Houtput, B. Svistunov, J. Tempere, N. Nagaosa, C. Franchini, A. S. Mishchenko, Phys. Rev. B 107, L121109 (2023).
[2] S. N. Klimin, J. Tempere, M. Houtput, S. Ragni, T. Hahn, C. Franchini, A. S. Mishchenko, Phys. Rev. B 110, 075107 (2024).
[3] M. Houtput, L. Ranalli, C. Verdi, S. Klimin, S. Ragni, C. Franchini, J. Tempere, Phys. Rev. B 111, 184320 (2025).

Confirmed invited speakers

• Marco Bernardi -  California Institute of Technology, USA
• Xavier Gonze - KU Leuven
• Alfredo Pasquarello - KU Leuven
• Julia Wiktor - Chalmers University of Technology, Sweden
• Stefano Ragni - Institute of Physics, Zagreb, Croatia
• Jarvist Frost - Imperial College London, UK
• Nikolay Prokof'ev - University of Massachusetts, USA
• Ali Gencer - Ankara University, Turkey
• Zhenbang Dai - University of Texas, USA
• Carlos Sa De Melo - Georgia Institute of Technology, USA
• Mona Berciu - University of British Columbia, Canada
• Hadrien Kurkjian - CNRS, France
• Bradley Martin - Imperial College London, UK

Organizers

Name	Affiliation
Serghei Klimin	Theory of Quantum systems and Complex systems (TQC), University of Antwerp, Belgium
Jacques Tempere	Theory of Quantum systems and Complex systems (TQC), University of Antwerp, Belgium
Matthew Houtput	Theory of Quantum systems and Complex systems (TQC), University of Antwerp, Belgium
Cesare Franchini	Faculty of Physics, Computational Materials Physics, University of Vienna, Austria