Speaker: Prof. Karolina Słowik, professer from the Nicolaus Copernicus University, Poland

Title: Light Interactions with Polar Quantum Systems

Time: 9:30 August 26th, 2025 (Tuesday)

Venue: No.4 conference room on the 3rd floor, Building No.5

Host: Prof. Xinfeng Liu

Info. of Speaker：

Karolina Maria Słowik, Dr. habil. (D.Sc. equivalent), is an Associate Professor at the Institute of Physics, Nicolaus Copernicus University in Toruń, Poland. Her research lies at the interface of quantum optics, nanophotonics, and material science, with a focus on light–matter interactions in low-dimensional and nanostructured systems. She has co-authored over 30 peer-reviewed publications, including articles in Nature Photonics, Nature Communications, and Physical Review X, with more than 400 citations. Dr. Słowik has been the PI or coordinator of several national and international research projects, including ERA-NET QuantERA, projects by Foundation for Polish Science, National Science Centre, Poland, Polish Ministry of Science and Higher Education, and DAAD–DFG bilateral program. In 2019, she was awarded the Ministry stipend for outstanding young researchers. She actively collaborates with leading groups in Germany, Spain, Italy, South Korea, and the USA. She serves on the Editorial Board of Scientific Reports and the Board of the Atomic, Molecular and Optical Physics Division of the European Physical Society. Beyond research, she is engaged in science outreach and mentoring, supervising doctoral and master students in quantum optics and nanophotonics.

Abstract:

The optical properties of atomic systems are shaped by their spatial symmetries, which are captured through multipolar transition moments. These values are tied to selection rules that determine which transitions can take place in a quantum system. In contrast, permanent multipolar moments are often brushed aside, assumed to cause only trivial energy shifts. This work explores light–matter interaction regimes where that assumption no longer holds.

A paradigmatic quantum effect altered in polar systems is the familiar Rabi population transfer. When it takes place between eigenstates that carry permanent dipole moments, it leads to an additional oscillating dipole—one that radiates at the Rabi frequency [1,2]. Interestingly, this frequency can be controlled across a broad spectral range, which opens the door to all-optically tunable sources of coherent radiation [3,4].

Permanent dipole moments also change how light couples to matter. In non-polar systems, the interaction strength grows linearly with the amplitude of the electric field. But in polar systems under strong fields, this scaling can shift—pointing to a new regime of coherent dynamics, potentially resilient even in the presence of strong spatial variations in the driving field [5-7].

[1] O. V. Kibis, G. Slepyan, S. A. Maksimenko, A. Hoffmann, Phys. Rev. Lett. 102, 023601 (2009).

[2] G. Scala, K. Słowik, P. Facchi, S. Pascazio, F. V. Pepe, Phys. Rev. A 104, 013722 (2021).

[3] I. Chestnov, V. A. Shahnazaryan, A. P. Alodjants, I. A. Shelykh, ACS Photonics 4, 2726-2737 (2017).

[4] P. Gładysz, P. Wcisło, K. Słowik, Sci. Rep. 10, 17615 (2020).

[5] P. Gładysz, K. Słowik, Phys. Rev. A 11 (5), 053704 (2025).

[6] F. Pepe, K. Słowik, Phys. Rev. Lett. 133 (8), 083603 (2024).