Missions

Hexagonal boron nitride (hBN) has recently emerged as a very promising two-dimensional material for quantum information applications. It combines high-quality single-photon sources with the ability to realise integrated photonic circuits, opening the way to efficient monolithic quantum processors.
The project is based on recent advances achieved by the team in the field of hBN nanostructuration, and will aim to remove the technological barriers towards top-down, fully deterministic fabrication that is compatible with scaling up. The aim is to build a fully integrated on-chip quantum optical device, from the emitters (B-center of h-BN) to the detector (SNSPDs in NbN) through BN waveguides.
The post-doc will develop, based on our previous results [1, 2, 3], the nanofabrication techniques of hBN photonic components (such as photonic crystals), in order to match the quantum emitter wavelength (SPE at 440nm). It will also enable the monolithic integration of NbN superconducting nanowire single photon detectors (SNSPDs), as well as the photonic enhancement of their efficiency.
For this, he/she will carry out time-based optical simulations (FDTD) to optimize the design of BN-based cavities and waveguides, at the emitter side as well as the detector one. He/she will then fabricate the devices in our 100m2 clean-room, thanks to our just-installed 100keV ebeam lithography system (with hBN exfoliation and transfer). The samples will be characterized by our partner at GEMaC, with whom the candidate will strongly interact to improve the results.
The post-doc will benefit from an excellent environment on a state-of-the-art equipment, as well as a scientific environment dedicated to quantum technologies, locally at LPENS, and also with our partners in Paris and Paris region.

1 C. Fournier et al., Position-controlled quantum emitters with reproducible emission wavelength in hexagonal boron nitride, Nat. Comm. 12, 3779 (2021)
2 D. Gérard et al., Quantum efficiency and vertical position of quantum emitters in hBN determined by Purcell effect in hybrid metal-dielectric planar photonic structures, ACS Photonics 11, 5188 (2024)
3 D. Gérard et al., Top-down integration of a hBN quantum emitter in a monolithic photonic waveguide, APL 122, 264001 (2023)

Activités

- FDTD simulations
- Nanofabrication in clean room, with exfoliation, transfer, electronic lithography of hexagonal boron nitride, and metal deposition
- Presentation of the obtained results to our partners, in international conferences and in peer-reviewed articles

Compétences

- PhD in experimental condensed matter physics, nanomaterials science, or a related field. (ideally in the last 2 years)
- Experience in clean-room device fabrication techniques and/or 2D materials handling is a plus
- Good communication skills in English (minimum B2-level)
- Good organisation and communication skills, self-motivated work
- Taste and motivation for collaborative work

Contexte de travail

LPENS is one of the 2 research laboratories of the Physics department of the Ecole Normale Supérieure. 90 researchers, 60 engineers/technicians and 180 PhD students and postdoctoral researchers are working there. It is a laboratory with strong experimental activities in condensed matter and quantum physics.
The postdoctoral researcher will be hosted by the Clean room team, composed of 3 engineers. The clean room, with a 120m2 area and around fifteen equipments, hosts around 50 users per year, mainly PhD students and postdoctoral researchers from the LPENS, but also from other labs of Paris. The platform has developed a recognized know-how in bidimensional materials nanostructuration (graphene, hBN, TMDC) and in the fabrication of quantum devices based on super- and semiconductors.
The clean room is part of the Groupement of Micro and
Nanotechnology Platforms of Paris (GPNP) (https://gpnp.obspm.fr/).
This project is granted by the ANR with partners at GEMaC (Versailles university, Aymeric Delteil) and at LPEM (ESPCI, Chéryl Feuillet-Palma).