Room-temperature single photon emission from micron-long air-suspended carbon nanotubes

TL;DR

This study demonstrates room-temperature single photon emission from micron-long air-suspended carbon nanotubes, showing their potential as high-purity quantum photon sources through photon correlation measurements and theoretical analysis.

Contribution

It provides the first detailed analysis of photon antibunching in air-suspended nanotubes at room temperature, including experimental results and a theoretical model.

Findings

Achieved $g^{(2)}(0) < 0.5$, confirming single photon emission.

Identified optimal excitation power for minimal $g^{(2)}(0)$.

Developed a Monte Carlo simulation and analytical model for exciton dynamics.

Abstract

Statistics of photons emitted by mobile excitons in individual carbon nanotubes are investigated. Photoluminescence spectroscopy is used to identify the chiralities and suspended lengths of air-suspended nanotubes, and photon correlation measurements are performed at room temperature on telecommunication-wavelength nanotube emission with a Hanbury-Brown-Twiss setup. We obtain zero-delay second-order correlation $g^{(2)}(0)$ less than 0.5, indicating single photon generation. Excitation power dependence of the photon antibunching characteristics is examined for nanotubes with various chiralities and suspended lengths, where we find that the minimum value of $g^{(2)}(0)$ is obtained at the lowest power. The influence of exciton diffusion and end quenching is studied by Monte Carlo simulations, and we derive an analytical expression for the minimum value of $g^{(2)}(0)$. Our results indicate that mobile excitons in micron-long nanotubes can in principle produce high-purity single photons, leading to new design strategies for quantum photon sources.