SKM 2023 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 49: Quantum dots: Devices

HL 49.1: Talk

Friday, March 31, 2023, 09:30–09:45, POT 151

Gate-based protocol simulations for quantum repeaters using quantum-dot molecules in switchable electric fields — •Steffen Wilksen, Frederik Lohof, and Christopher Gies — Institute for Theoretical Physics, University of Bremen, Bremen, Germany

Semiconductor quantum dots provide a promising platform for applications in quantum information technologies, such as quantum repeaters, which enable secure quantum communication over long distances. Two quantum dots, separated by a small tunnelling layer, form a so-called quantum dot molecule (QDM), which exhibits properties similar to classical molecules. Their energy levels can be tuned by applying an external electric field, thereby allowing to perform gate operations. We consider QDMs in switchable electric fields towards quantum-repeater realizations. The time dependence that arises from performing gate operations requires a careful treatment of the system-bath interaction. We treat the QDM as an open quantum system using an explicitly time-dependent Redfield master equation approach, accounting for the time dependence of the interaction rates beyond more simple Lindblad approaches. Based on our approach, we investigate the adiabatic and non-adiabatic behaviour of the system for different switching speeds and determine achievable execution times for gate operations with currently existing QDMs.