Philippe Goldner visited the Karlsruher Institute of Technology (KIT) where he gave a seminar entitled 'Emerging rare earth-based platforms for optical quantum technologies'. He also took the chance to visit Pr. David Hunger's group (in the picture).

In this we investigate the optical and spin properties of 171Yb3+ ions in LiNbO3 bulk crystals as well as implanted waveguides. Using hole-burning spectroscopy and optically detected magnetic resonance, we studied ground and excited state hyperfine structures and probed optical and spin spectral holes. Importantly, the hole linewidths suggest that part of the ions in the waveguides are in a similar environment as in the bulk sample. We furthermore characterized spin population relaxation and coherence lifetimes of 171Yb3+ ions in the bulk crystal at temperatures between 50 mK and 9 K. At low temperatures, T2 up to 9.5 μs (34 kHz homogeneous linewidth) and spin relaxation rates as long as ≈100 ms were measured.

​

Link to article

The silver medal recognizes researchers for the originality, quality and importance of their work, recognized nationally and internationally.

In this paper, we report on europium molecular crystals that exhibit linewidths in the tens of kilohertz range, orders of magnitude narrower than those of other molecular systems. We harness this property to demonstrate efficient optical spin initialization, coherent storage of light using an atomic frequency comb, and optical control of ion–ion interactions towards implementation of quantum gates. These results illustrate the utility of rare-earth molecular crystals as a new platform for photonic quantum technologies that combines highly coherent emitters with the unmatched versatility in composition, structure and integration capability of molecular materials.

Check press release, reports and interviews also in  French!

This new birefringence measurement tool is composed of a camera mounted onto a microscope. It has been acquired thanks to the support of the regional network on quantum technologies SIRTEQ . Thanks to this instrument, strain and defects in diamond material can be imaged at the microscopic scale. It is particularly critical since they are known to affect the performance of diamond based sensors that use colour centres in this material.

In this new paper we study the properties of CVD grown europium doped Y2O3 thin films. We apply a series of annealing post-treatment on a multi-layer architecture to improve the optical properties. We achieve a record ultra-narrow homogeneous linewidth of 5 MHz inferred from spectral hole width. The results are published in Materials Advances.

This Equipex project is coordinated by ENS Paris Saclay (JF Roch) and gathers several academics and one company. It will allow us to mature the technologies that use diamod colour centres for magnetic sensing. The project will address the entire fabrication chain from the diamond synthesis to the end-user of the device. In our team we will be equipped with an implantation and post-treatment system. To know more

We are glad to welcome in the team two new PhD students: Pauline Perrin, former student from EC Lyon and working on hybrid rare-earth diamond materials, and Valentin Grand d'Esnon, former student at Chimie Paristech, and working on Rare-earth nanoparticles for quantum technologies.

Nao Harada successfully defended his PhD thesis on October 19, 2021. Congratulations! He gave a presentation on the elaboration of rare earth doped thin film oxide by CVD for quantum optical technologies. This 3-year PhD project has been funded by the SQUARE project (EU flagship).

This article, entitled "Dynamic control of Purcell enhanced emission of erbium ions in nanoparticles" uses fast modulation of the resonance frequency of a fiber coupled micro-cavity to change the emission properties of erbium doped nanoparticles. This work is a collaboration with the ICFO (Barcelona, Spain) and KIT (Karlsruhe, Germany) institutes.

​

Link to the paper. 

This work done in collaboration with the Karlsruhe Institut of Technology (Germany) and the University of Strasbourg (France) is entitled "Optical spin-state polarization in a binuclear europium complex towards molecule-based coherent light-spin interfaces". It reports a first measurement of optical homogeneous linewidth in a rare-earth molecular crystal, demonstrating also optical nuclear spin-state initialization.

​

Link to the paper. 

The projet RareDiamond has been selected in the ERC Advanced Grant call 2020. We will develop new hybrid materials that combine rare earth ions and color centrer in diamond.

links: ERC - CNRS - Chimie ParisTech 

Philippe receives one of the 'Etoiles de l'Europe' (Stars of Europe) awards from the French Ministry of Higher Education and Research, for his coordination work in NanOQTech and engagement with EU research. The awards ceremony took place on December 16, 2020.