Regensburg 2013 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 29: Poster Session: Spintronics; Spin-controled transport; Topological insulators; Interfaces / Surfaces; Magnetic semiconductors

HL 29.10: Poster

Montag, 11. März 2013, 16:00–20:00, Poster A

Magnetic-Field Contol of Photon Echo from the Electron-Trion System in a CdTe Quantum Well: Shuffling Coherence between Optically Accessible and Inaccessible States — •Lukas Langer¹, Sergey V. Poltavtsev^1,2, Irina A. Yugova^1,2, Dmitri R. Yakovlev^1,3, Grzegorz Karczewski⁴, Tomasz Wojtowicz⁴, Jacek Kossut⁴, Ilya A. Akimov^1,3, and Manfred Bayer¹ — ¹Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany — ²Spin Optics Laboratory, St. Petersburg State University, 198504 St. Petersburg, Russia — ³A.F. Ioffe Physical-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia — ⁴Institute of Physics, Polish Academy of Sciences, PL-02668 Warsaw, Poland

We report on magnetic field-induced oscillations of the photon echo signal from negatively charged excitons in a CdTe/(Cd,Mg)Te semiconductor quantum well. The oscillatory signal is due to Larmor precession of the electron spin about a transverse magnetic field and depends sensitively on the polarization configuration of the exciting and refocusing pulses. The echo amplitude can be fully tuned from the maximum down to zero depending on the time delay between the two pulses and the strength of the magnetic field. The results are explained in terms of the optical Bloch equations accounting for the spin level structure of electrons and trions.