Exciton Coherence in CsPbBr3 Nanocrystals is Bounded by Phonon-Mediated Bright-Triplet Relaxation
Abstract
Scalable sources of indistinguishable single photons or entangled photon pairs are fundamental to many quantum photonic technologies. Colloidal lead halide perovskite nanocrystals are promising such sources, but their exciton coherent properties are not fully understood. We show that in single CsPbBr3 nanocrystals at 4 K, acoustic phonon-mediated exciton fine structure relaxation (EFSR) drives leakage of population between the bright exciton triplet states, competing with the radiative lifetime. The leakage pathway reaches 0.64 ± 0.04 of the radiative rate, bounding state coherence to 0.81 times the transform limit at 4 K. This pathway is intrinsic to the nanocrystal, not its environment, making it a tractable target for materials and device design. We identify fine structure and acoustic phonon engineering as effective intrinsic routes to higher coherence in perovskite quantum light sources.
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BibTeX
@misc{sverko2026exciton,
title = {{Exciton Coherence in CsPbBr3 Nanocrystals is Bounded by Phonon-Mediated Bright-Triplet Relaxation}},
author = {Tara Šverko and Annette J. Jones and Chantalle J. Krajewska and Peter C. Sercel and Alexander L. Efros and Alexander E. Kaplan and Niamh L. Brown and Stefano Toso and Moungi G. Bawendi},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.07739},
eprint = {2609.07739},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.07739},
}
RIS
TY - UNPB
TI - Exciton Coherence in CsPbBr3 Nanocrystals is Bounded by Phonon-Mediated Bright-Triplet Relaxation
AU - Tara Šverko
AU - Annette J. Jones
AU - Chantalle J. Krajewska
AU - Peter C. Sercel
AU - Alexander L. Efros
AU - Alexander E. Kaplan
AU - Niamh L. Brown
AU - Stefano Toso
AU - Moungi G. Bawendi
PY - 2026
DA - 2026/09/07
PB - arXiv
DO - 10.48550/arxiv.2609.07739
UR - https://arxiv.org/abs/2609.07739
AB - Scalable sources of indistinguishable single photons or entangled photon pairs are fundamental to many quantum photonic technologies. Colloidal lead halide perovskite nanocrystals are promising such sources, but their exciton coherent properties are not fully understood. We show that in single CsPbBr3 nanocrystals at 4 K, acoustic phonon-mediated exciton fine structure relaxation (EFSR) drives leakage of population between the bright exciton triplet states, competing with the radiative lifetime. The leakage pathway reaches 0.64 ± 0.04 of the radiative rate, bounding state coherence to 0.81 times the transform limit at 4 K. This pathway is intrinsic to the nanocrystal, not its environment, making it a tractable target for materials and device design. We identify fine structure and acoustic phonon engineering as effective intrinsic routes to higher coherence in perovskite quantum light sources.
ER -