PhD : As-based quantum dots epitaxy (M/F)

Job Description

Thesis Subject

The objective of this thesis is to start the development of single-photon sources (SPS) emitting at telecom wavelengths, a critical advancement necessary for enabling long-distance quantum communications and the realization of a photonic quantum processor. Using photons as qubits is interesting because they exhibit low decoherence. When their energies are in the telecom range, they are also compatible with existing optical infrastructure, enabling high-speed, low-loss information transfer.
This makes them ideal for quantum communication over extended distances. As silicon is transparent in this spectral range, it is also possible to build on the extraordinary progress made in silicon-on-insulator technology to realize a photonic quantum processor. Unfortunately, at present, there is no source capable of emitting indistinguishable "telecom" single photons on demand. This is essential to enable photon coalescence, a fundamental phenomenon at the heart of quantum repeaters for quantum communication, or to generate entanglement in a photonic integrated circuit for the photonic quantum processor, the building blocks for the future quantum internet.
The aim of this stage is to tackle this issue, by developing new approaches to the epitaxy of arsenide-based semiconductor quantum dots (QDs) to create an ideal source of single photons. We will explore an innovative way of growing these structures by molecular beam epitaxy. The process involves the formation of Group III metal nanodroplets, enabling local etching of a III-As substrate forming a nanohole, followed by the QD formation through the nanohole filling. This novel approach should facilitate the synthesis of large, symmetrical QDs with a highly reproducible size and rapid optical emission, reducing sensitivity to environmental noise and providing a promising source of indistinguishable single photons. The work will involve optimizing the growth of QDs with the LDE method to achieve emission at telecom wavelength.

Your Work Environment

Institut NÉEL is a CNRS unit (UPR 2940) under agreement with the University Grenoble Alpes. The laboratory is related to the CNRS Physique. It is located in Grenoble, in the heart of a unique scientific, industrial and cultural environment. It is one of the largest French national research institutes for fundamental research in condensed matter physics enriched by interdisciplinary activities at the interfaces with chemistry, engineering and biology. It consists of 450 employees, including 175 researchers.
CNRS is a public, scientific and technological organization.
The core mandate is to identify, to carry out or to have carried out, either alone or with partners, all research that advances science or contributes to the country's economic, social, and cultural progress. Internationally recognized for the excellence of its scientific research, the CNRS is a reference in the world of research and development, as well as for the general public.

This thesis will be conducted within the Nanophysics and Semiconductors Group, as part of a joint CEA-CNRS team, with access to equipment at both centers. It will focus on the MBE growth of arsenide quantum dot samples via LDE. Characterization methods such as photoluminescence, AFM, X-ray diffraction (XRD), and scanning electron microscopy (SEM) and transmission electron microscopy (TEM) will also be used to understand the characteristics of the samples obtained. Similarly, simulations of the electronic structure of the quantum dots will be essential for understanding their behavior.

The hosting team at Institut Néel is NPSC, which forms part of the PLUM department.

Constraints and risks

This position involves handling hazardous chemicals, nanomaterials, cryogenic systems, and lasers.

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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