# InAs quantum dot in a needlelike tapered InP nanowire: a telecom band single photon source monolithically grown on silicon

## TL;DR

This paper demonstrates the monolithic growth of InAs/InP quantum dot nanowires on silicon, producing telecom-band single photon sources with high purity and controlled emission properties, suitable for integrated quantum photonics.

## Contribution

It introduces a controlled growth method for tapered InAs/InP nanowires on silicon, optimizing their geometry for telecom-band single photon emission.

## Key findings

- Room temperature telecom-band emission with 30° divergence
- Single photon purity with g²(0)=0.05 at cryogenic temperature
- Effective monolithic integration of quantum dot nanowires on silicon

## Abstract

Realizing single photon sources emitting in the telecom band on silicon substrates is essential to reach complementary-metal-oxide-semiconductor (CMOS) compatible devices that secure communications over long distances. In this work, we propose the monolithic growth of needlelike tapered InAs/InP quantum dot-nanowires (QD-NWs) on silicon substrates with a small taper angle and a nanowire diameter tailored to support a single mode waveguide. Such a NW geometry is obtained by a controlled balance over axial and radial growths during the gold-catalyzed growth of the NWs by molecular beam epitaxy. This allows us to investigate the impact of the taper angle on the emission properties of a single InAs/InP QD-NW. At room temperature, a Gaussian far-field emission profile in the telecom O-band with a 30{\deg} beam divergence angle is demonstrated from a single InAs QD embedded in a 2{\deg} tapered InP NW. Moreover, single photon emission is observed at cryogenic temperature for an off-resonant excitation and the best result, $g^2(0) = 0.05$, is obtained for a 7{\deg} tapered NW. This all-encompassing study paves the way for the monolithic growth on silicon of an efficient single photon source in the telecom band based on InAs/InP QD-NWs.

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Source: https://tomesphere.com/paper/1906.11708