Berlin 2024 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 43: Optical Properties II

HL 43.4: Talk

Thursday, March 21, 2024, 10:15–10:30, EW 561

Intensity modulation of a light beam by excitation of 1S-excitons in Cu₂O in a cavity — •Simon Siegeroth, Binodbihari Panda, Mariam Harati, Julian Heckötter, and Marc Aßmann — Department of physics, TU Dortmund, Dortmund 44227, Deutschland

Excitons in Cu2O are a suitable platform to study Rydberg physics. By reaching a high principal quantum number up to 25[1], many characteristic properties increase by orders of magnitude compared to ground state excitons, such as the radius (r∝n²), the lifetime (t∝n³) or the blockade volume (V∝n⁷). Here we report on the interaction between Rydberg excitons and ground state excitons (1S). By exciting 1S-exctions via a two-color pump probe setup we observed modulation of the laser intensity of the transmitted probe beam in spectral dependency. The modulation is dependent on pump laser energy & power and also visible in the reflected probe beam. This phenomenon is investigated for a set of parameters such as pump-power, angle, probe-polarization, probe-power and overlap. The oscillations do only appear when the sample is mounted strain free between two glass plates with a low reflectivity of around 4% at each surface which are forming a (bad) cavity. Interestingly the oscillations appear as well when the probe laser is tuned out of resonance.

[1] T. Kazimierczuk, D. Fröhlich, S. Scheel, H. Stolz, and M. Bayer. "Giant Rydberg excitons in the copper oxide Cu2O." Nature 514 (2014), pp. 343-347.

Keywords: Exciton; Rydberg-Exciton; Cu2O