Phonon Wave Packet Emission during State Preparation of a Semiconductor Quantum Dot using Different Schemes

• Published in: physica status solidi (b) Vol. 259; no. 6
• Main Authors: Bracht, Thomas K., Seidelmann, Tim, Kuhn, Tilmann, Axt, Vollrath Martin, Reiter, Doris E.
• Format: Journal Article
• Language: English
• Published: 01.06.2022
• Subjects: electron–phonon interaction; quantum dots; state preparation; two-level system
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.202100649

The carrier–phonon interaction in semiconductor quantum dots (QDs) can greatly affect the optical preparation of the excited state. For resonant excitation used in the Rabi preparation scheme, the polaron is formed accompanied by the emission of a phonon wave packet, leading to a degradation of preparation fidelity. In this article, phonon wave packets for different coherent excitation schemes are analyzed. One example is the adiabatic rapid passage scheme relying on a chirped excitation. Herein, also a phonon wave packet is emitted, but the preparation fidelity can still be approximately unity. A focus is on the phonon impact on a recently proposed swing‐up scheme, induced by two detuned pulses. Similar to the Rabi scheme, a degradation and a phonon wave packet emission are found, despite the detuning. If the swing‐up frequency coincides with the maximum of the phonon spectral density, a series of wave packets is emitted yielding an even stronger degradation. The insight gained from our results further helps in designing an optimal preparation scheme for QDs. The excitation of a semiconductor quantum dot is strongly influenced by its interaction with the environment. The impact of phonons on different optical excitation schemes—resonant excitation, adiabatic rapid passage, and the two‐color off‐resonant swing‐up of emitter population (SUPER) scheme—is compared and the emitted phonon wave packets are analyzed.