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HL: Fachverband Halbleiterphysik

HL 75: Poster IIIB

HL 75.8: Poster

Donnerstag, 19. März 2020, 15:00–17:30, P2/3OG

Simulating the influence of spectral jitter and phonons on four-wave mixing signals of single quantum dots — •Thilo Hahn, Daniel Wigger, and Tilmann Kuhn — Institut für Festkörpertheorie, Universität Münster, Wilhelm-Klemm-Str. 10, 48149 Münster

Four-wave mixing (FWM) micro-spectroscopy is a powerful technique to investigate the dynamics of charge carriers in semiconductor nanostructures. By using a heterodyne interferometry technique one is able to detect coherence as well as occupation dynamics of a single quantum dot [1]. We model the QD exciton as a two-level system, excited by a series of ultrafast pulses. Additionally we take the pure dephasing coupling to a discrete phonon mode into account. By introducing characteristic functions the dynamics of the entire exciton-phonon system can be calculated analytically in the limit of ultrafast optical excitation [2]. We will present photon echo formation as a consequence of a randomization of the transition energy due to for example charge fluctuations [3]. Then we take the coupling to a discrete phonon mode into account and discuss its impact on FWM signals.

[1] W. Langbein, Rivista Del Nuovo Cimento 33, 5 (2010)

[2] A. Vagov, et al., Phys. Rev. B 66, 165312 (2002)

[3] T. Jakubczyk, et al., ACS Photonics 3, 2461-2466 (2016)