Complex Photonic Systems with Broken Symmetries: Synergetic Effects of Wave Chaos and Non-Hermiticity

Photonic devices are intrinsically open wave systems described by the language of non-
Hermitian physics. Devices such as passive and active microcavities and photonic crystals
have served as important testbeds for examining and developing theories of wave chaos
in open systems and non-Hermitian physics. The workshop and seminar COPH25 aimed
to share insights, explore new research directions, and foster collaborations in the field of
complex photonic systems, where wave chaos theory and/or non-Hermitian physics play
essential roles.
The main topics and key speakers of the workshop and seminar are the following:
Wave chaos theory (K. Richter, R. Ketzmerick, T. Harayama, C.-H. Yi); Non-Hermitian
physics (N. Hatano, H. Schomerus, J. Wiersig, B. D´ora, E.-M. Graefe); Topological effects
in photonics (A. Altland, S.S. Oh, C. Wanjura); Electromagnetic-wave experiments (H.-J.
Stöckmann, B. Dietz, F. Mortessagne, U. Kuhl); Photonic experiments (M. Lebental, M.
Choi, S. Sunada).
H.-J. Stöckmann delivered a PKS colloquium talk, providing an overview of his experimental
studies of quantum/wave chaos. N. Hatano and H. Schomerus presented introductory
lectures for students and young scientists on non-Hermitian physics, while B.
Dietz offered a similar introductory lecture on wave chaos.
Approximately 40% of the attendees were young scientists (i.e., graduate students and
postdocs), and almost all of them made oral and/or poster presentations. We encouraged
contributed talk speakers, primarily young scientists, to also present a poster to increase
opportunities for in-depth discussions. This initiative proved to be very successful, as
evidenced by the lively interactions between young and senior scientists observed during
the poster sessions in both weeks.
In addition to their oral and poster presentations, young researchers benefited from
dedicated mentoring sessions and informal discussions with senior scientists. These activities
provided valuable guidance on research directions, fostered career development,
and encouraged the exchange of ideas across different research backgrounds. Such interactions
greatly enhanced the learning experience and strengthened the international
network among early-career participants. The social events, a visit to the silver mine in
Freiberg with a guided city tour and the conference dinner in the Carolaschlösschen as
well as a beer garden dinner in the second week, nicely supported this and contributed to
the creative and cooperative atmosphere of the COPH25 workshop and seminar.
In conclusion, we brought together leading experts, both theorists and experimentalists,
in the fields of wave chaos and non-Hermitian physics. This created exciting opportunities
for participants to connect with peers internationally, exchange ideas, exploiting
synergies, and contribute to ongoing discussions at the forefront of these fields.
 

We would like to thank the MPIPKS Visitors Program for its support, especially the
excellent assistance provided by Mandy Lochar.