Ultra-Efficient Coupling of a Quantum Emitter to the Tunable Guided Plasmons of a Carbon Nanotube

TL;DR

This paper demonstrates near-perfect coupling of a quantum emitter to tunable plasmons in a doped carbon nanotube, enabling efficient quantum interactions and strong coupling potential in nanoscale photonic devices.

Contribution

It introduces a highly efficient, tunable coupling mechanism between quantum emitters and plasmons in carbon nanotubes, with near-unity beta factor and extremely high Purcell enhancement.

Findings

Coupling efficiency approaches 100% over broad spectral range.

Beta factor approximately 1 for emitters 1-100 nm from nanotubes.

Purcell factor exceeds 10^6.

Abstract

We show that a single quantum emitter can efficiently couple to the tunable plasmons of a highly doped single-wall carbon nanotube (SWCNT). Plasmons in these quasi-one-dimensional carbon structures exhibit deep subwavelength confinement that pushes the coupling efficiency close to 100% over a very broad spectral range. This phenomenon takes place for distances and tube diameters comprising the nanometer and micrometer scales. In particular, we find a beta factor ~1 for QEs placed 1-100 nm away from SWCNTs that are just a few nanometers in diameter, while the corresponding Purcell factor exceeds 10^6. Our finding not only holds great potential for waveguide QED, in which an efficient interaction between emitters and cavity modes is pivotal, but it also provides a way of realizing quantum strong coupling between several emitters mediated by SWCNT plasmons, which can be controlled through the large electro-optical tunability of these excitations.