PGI Kolloquium:Prof. Dr. Manfred Bayer, TU Dortmund University, Germany

PGI Lecture Hall, Building 04.8, 2nd Floor, Room 365

Rydberg Excitons in Cuprous Oxide: Excitants determine the optical properties of semiconductors and insulators. Their description as hydrogen atom-like complexes has turned out to be an extremely successful concept.

Excitants determine the optical properties of semiconductors and insulators. Their description as hydrogen atom-like complexes has turned out to be an extremely successful concept. In Rydberg atoms an electron is promoted into a state with very high principal quantum number. Thereby the atom may become a mesoscopic quantum object with dimensions in the micrometer-range. Recently it was shown that also an exciton can be highly excited by observing states with principal quantum number up to n=25 in natural cuprous oxide crystals [1].

This corresponds to an average radius of more than 1 µm so that the exciton wave function covers more than 10 billion crystal unit cells. In the talk similarities to and differences from atoms will be addressed for these Rydberg excitons. Examples are their level splitting in electric and magnetic fields [2], quantum chaos in magnetic field [3], many-body interactions with other carriers as well as quantum optical effects like the Rydberg blockade or dressed state formation [4]. 

[1] T. Kazimierczuk, D. Fröhlich, S.Scheel, H. Stolz, and M. Bayer, Nature 514, 343 (2014).

[2] J. Thewes, J. Heckötter, T. Kazimierczuk, M. Aßmann, D. Fröhlich, M. Bayer, M. A. Semina, and M. M. Glazov, Phys. Rev. Lett. 115, 027402 (2015).

[3] M. Assmann, J. Thewes, D. Fröhlich, and M. Bayer, Nature Materials 15, 741 (2016).

[4] P. Grünwald, M. Aßmann, J. Heckötter, D. Fröhlich, M. Bayer, H. Stolz, and S. Scheel, Phys. Rev. Lett. 117, 133003 (2016).

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