Missions

The Q-META project aims to control and improve the emission properties of quantum emitters with 2D optical metasurfaces, well beyond the performance offered by unique state-of-the-art nanoantennas. To do this, non-classical light nanosources will be precisely positioned in the near field of 2D dielectric arrays (metasurfaces). The latter will be specifically designed to control the directivity, brilliance, chirality, polarization of the QE emission by coupling to localized and collective resonances, in the visible/near infrared.

Activities

In this project, the quantum emitters will be colored centers in colloidal nanodiamonds, with typical diameters of a few tens of nanometers. The NV centers will be used as a priority, but other colored centers available at CEMES will also be considered (collaboration with an academic partner).

- The dielectric metasurfaces will be designed and manufactured by ebeam lithography on silicon-on-insulator (SOI) substrates, thanks to an active collaboration with the LAAS laboratory in Toulouse (the candidate will not be directly involved in these steps).

- The spatial and quantitative positioning of the fluorescent emitters in the 2D periodic structure of the metasurfaces will be carried out by a directed assembly technique called AFM nanoxerography. This technique, at the heart of this postdoctoral subject, was developed in the LPCNO Nanotech team. It is based on the local injection of electrostatically charged points via a polarized tip positioned above the areas of interest. These charged points will act as selective electrostatic traps for the emitters. The two laboratories (CEMES-LPCNO) involved in this project have recently demonstrated the deterministic and reproducible positioning of nanodiamonds on a flat SiO2/Si film and on simple Si nanoantennas.

-Once the hybrid emitter-metasurface systems have been produced, the candidate will characterize the modification of the photodynamics of the emitters as a function of the wavelength and the orientation of the dipole, by 2D mapping of the time-resolved photoluminescence. The control of directivity and polarization will be evaluated by imaging the polarization-resolved Fourrier plane. These optical characterizations will be carried out at CEMES on state-of-the-art time-resolved confocal microscopes. The experimental results will be systematically supported by numerical simulations (GDM).

Skills

The candidate will hold a doctorate in nano-optics, plasmonics, nanotechnologies or near-field probes with a solid background in general physics, electromagnetism and light-matter interaction. He/she will have strong skills in experimental research, and prior experience in optical microscopy and/or AFM. Autonomy, dynamism, scientific curiosity and rigor are the key words to carry out this project.

Work Context

He or she will be hosted by the NeO team at CEMES and the Nanotech team at LPCNO in Toulouse (France). The candidate will be involved in the experimental aspects of (i) the electrical and topographical modes of AFM, (ii) the process of directed assembly of quantum emitters by nanoxerography, (iii) optical characterization at the single photon scale (quantum regime), and the theoretical aspects of (iv) the methods of electrodynamic simulation.

The position is located in a sector under the protection of scientific and technical potential (PPST), and therefore requires, in accordance with the regulations, that your arrival is authorized by the competent authority of the MESR.

Constraints and risks

The candidate will work on the CEMES and LPCNO sites approximately 1 km apart. Risks: use of lasers.