Cooperative emission from two coupled solid-state quantum emitters and its effect on random number generation

Madhura Ghosh Dastidar, Aprameyan Desikan, Gniewomir Sarbicki, Vidya Praveen Bhallamudi

Published 2024-08-03Version 1

We discuss the behaviour cooperative effects in the emitted light from a system of two nitrogen-vacancy (NV) centers confined in a nanopillar having dimensions close to the wavelength of the excitation pump. We experimentally observe a $g^{(2)}(0) > 0.5 \to 1$ for the coupled emitter system and a drastic decrease in the singlet and triplet lifetimes by a factor of $\approx 6$, indicating an interaction between the two emitters, which indicates superradiant behaviour. We theoretically study the dissipative dynamics of the interaction of the emitter system with the excitation light at a finite temperature for three cases (single emitter, two emitters with and without dipole-dipole coupling) by solving the Lindblad master equation and providing an analytical expression for the second-order correlation function. We observe that from the master equation, the populations and coherences mix for the two emitters' cases. Through this, we support our experimental results and discuss superradiance from our system. Finally, we discover a reliable quantum random number generation rate of $\sim 200$ kHz from the coupled emitter system, at low pump powers.