Berlin 2015 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 21: Poster IB (Oxide semiconductors; II-VI and group IV semiconductors; Nanotubes and Buckyballs)

HL 21.11: Poster

Montag, 16. März 2015, 15:00–20:00, Poster B

Stark-Effect Measurements on Giant Rydberg Excitons in Cuprous Oxide — •Johannes Thewes¹, Julian Heckötter¹, Marc Assmann¹, Tomasz Kazimierczuk², Dietmar Fröhlich¹, and Manfred Bayer¹ — ¹Institut für Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany — ²Faculty of Physics, University of Warsaw, Poland

We report on Stark-effect measurements of Giant Rydberg excitons³ in Cu₂O with quantum numbers up to n = 25. These excitons have extensions up to 2 µm. As known from hydrogen, the dipole matrix elements for Δ n = 0 and Δ l = ± 1 grow quadratically with n. In Cu₂O, P-excitons are dipole-allowed. Due to the electric field-induced coupling of P-excitons to S- and D-excitons we observe P/S and P/D resonances in fields as low as 10  Vcm⁻¹. Measurements are done on a 30 µm sample with a single frequency dye laser (Δ E = 1 neV) at temperatures down to 1.2 K. Contrary to hydrogen, the Stark-effect measurements can be done in a longitudinal configuration (K_laser || E). — ³ T. Kazimierczuk et al. Nature 514, 343 (2014)