Year: 2025
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Beyond single-photon emission, generating correlated N -photon bundles, e.g., a photon pair, is essential for various quantum technologies including quantum teleportation and metrology. A widely explored approach exploits the radiative biexciton cascade in individual (mainly epitaxially grown) quantum dots (QDs). Here, we investigate such a cascade in colloidal CsPbBr 3 QDs, a scalable and solution-processable quantum-light emitter. By matching their size-dependent biexciton binding energies to their size-independent phonon energies, we demonstrate the generation of time-correlated and energy-degenerate photon pairs in large (>15 nm) QDs. Under pulsed excitation at 4 K, we observe pronounced photon bunching, with a g (2) (0) of up to 7 in Hanbury Brown and Twiss measurements. The excitation-density-dependent bunching is quantitatively reproduced by multicolor numerical calculations, suggesting the cascade involving biexciton and phonon-mediated exciton decay as origin of the photon pair. Our findings provide new insights into energy-degenerate photon-pair generation in these highly engineerable quantum-light emitters, marking important steps toward their application in quantum-information technologies.
Source: Nano Letters
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
OpenAlex ID: W4413884367