Excitonic Bloch-Siegert shift in CsPbI3 perovskite quantum dots
Abstract
Coherent interaction between matter and periodic light field induces both optical Stark effect (OSE) and Bloch-Siegert shift (BSS). Observing the BSS has been historically challenging, not only because it is weak but it is often accompanied by a much stronger OSE. Herein, by controlling the light helicity, we can largely restrict the OSE and BSS to different spin-transitions in CsPbI3 perovskite quantum dots, achieving room-temperature BSS as strong as 4 meV with near-infrared pulses. The ratio between the BSS and OSE magnitudes is however systematically higher than the prediction by the non-interacting, quasi-particle picture. With a model that explicitly accounts for excitonic effects, we quantitatively reproduce the experimental observations. This model depicts a unified physical picture of the interplay between the OSE, biexcitonic OSE and BSS in low-dimensional materials displaying strong many-body interactions, forming the basis for the implementation of these effects to information processing, optical modulation and Floquet engineering.
Cite
@article{arxiv.2208.10045,
title = {Excitonic Bloch-Siegert shift in CsPbI3 perovskite quantum dots},
author = {Yuxuan Li and Yaoyao Han and Wenfei Liang and Boyu Zhang and Yulu Li and Yuan Liu and Yupeng Yang and Jingyi Zhu and Kaifeng Wu},
journal= {arXiv preprint arXiv:2208.10045},
year = {2022}
}