Manipulating Coherent Exciton Dynamics in CsPbI3 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 modulation of the polarization of these excitons in CsPbI3 QDs and manipulation of their time-domain coherent dynamics using a longitudinal magnetic field are demonstrated. The manipulation is realized using femtosecond quantum beat spectroscopy performed with both circularly- and linearly-polarized pulses. The results are well captured by the 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.

Automated summary

Lead halide perovskite quantum dots (QDs) have shown promise for quantum information processing due to their strong light-matter interaction and long-lived optical and spin coherences. This study demonstrates the modulation of polarization and manipulation of time-domain coherent dynamics of excitons in CsPbI3 QDs using a longitudinal magnetic field. The results, captured using femtosecond quantum beat spectroscopy and visualized using a Bloch sphere, provide a foundation for preparing coherent superpositions of excitons in perovskite QDs for quantum technologies.