Manipulating Coherent Exciton Dynamics in CsPbI 3 Perovskite Quantum Dots Using Magnetic Field.

Lead halide perovskite quantum dots (QDs) have recently emerged as a promising material platform for quantum information processing owing to their strong light-matter interaction and relatively long-lived optical and spin coherences. In particular, the coherence of the fine-structure bright excitons is sustainable up to room temperature and can be observed even at an ensemble level. Here we demonstrate modulation of the polarization of these excitons in CsPbI 3 QDs and manipulation of their time-domain coherent dynamics using a longitudinal magnetic field. The manipulation is realized using femtosecond quantum beat spectroscopy performed with both circularly- and linear-polarized pulses. The results are well captured by our density of matrix simulation and are picturized using a Bloch sphere. This study forms the basis for preparing arbitrary coherent superpositions of excitons in perovskite QDs for an array of quantum technologies under near-ambient conditions. This article is protected by copyright. All rights reserved.