Teaching activites
Academic interests
I am a laser physicist currently involved in the positronium activities of the AEgIS collaboration located at the antiproton decelerator at CERN. The goal of AEgIS is to study the effect of the Earth's gravitational field on antihydrogen using antimatter wave interferometry. Between 2020 and 2024, I led the Ps laser cooling NFR project which resulted in the first demonstration of positronium Doppler laser cooling performed with the AEgIS collaboration.
Background
I graduated my PhD from Paris Sud XI University in the attosecond physics group of SPAM (IRAMIS/CEA-Saclay) under the supervision of Pascal Salières and Thierry Ruchon. During my PhD, I introduced the use of Diffractive Optical Elements to shape femtosecond pulses and realize a simple, robust and very stable XUV interferometer. I used this interferometer to study electronic dynamics in aligned molecules with attosecond time resolution and Angstrom spatial resolution.
After my PhD, I joined the DiMauro-Agostini group at the Ohio University University (Columbus, OH) for a 3 years postdoctoral stay. There I took part in mid-infra red driven high-order harmonic generation for in-situ molecular spectroscopy. I was given the opportunity to continue my own research line on Diffractive Optical Elements for shaping mid-infrared femtosecond pulses. I initiated collaborations with other groups to study Fano resonances in Neon, generate femtosecond beams carrying OAM (Orbital Angular Momentum) from Difference Frequency Generation and the transfer of OAM during High-order Harmonic Generation. Finally, I took part in a time-resolved Auger decay experiment at SLAC using the X ray Free Electron Laser LCLS facility.
At the end of my postdoctoral stay, I was awarded a 3 years COFUND fellowship from CERN and the Marie Curie 2020 actions program. I joined the AEgIS collaboration based at the antiproton decelerator. There I took part in the antihydrogen production runs of 2017 and 2018. In AEgIS, a charge exchange mechanism is used to produce antihydrogen. It consists in transferring a positron from a Rydberg state positronium to an antiproton. Nanosecond lasers are used to populate the positronium Rydberg states. I took part in experimental efforts related to the development of a position sensitive imaging of positronium atoms and to the production of a metastable 23S beam of positronium.
Research activities
The AEgIS collaboration on Wikipedia
2024.12.12 The Physics World magazine has named my work with the AEgIS collaboration on positronium laser cooling as one of the Top 10 Breakthroughs of 2024.
2024.11.27 Our work on the alexandrite laser system used for the first positronium laser cooling demonstration is now publised in Optics and Laser Technology.
2024.10.25 In today's episode of Forskningsfronten, you can listen (in Norwegian) to what researchers are trying to achieve at CERN's antimatter factory. Many thanks to Torkild Jemterud for giving me this opportunity to report on the work of the AEgIS collaboration!
2024.07.10 Together with Jan Malamant and colleagues, we publish a study on new laser cooling schemes in PRA. Using spectrally shaped trains of pulses, we propose a solution to minimize the time it takes to laser cool atoms or molecules with large initial velocity distributions. This could be very useful to cool species such as positronium with a limited lifetime (142 ns annihilation lifetime in the case of positronium).
2024.02.22 First demonstration of positronium laser cooling achieved by the AEgIS collaboration published in PRL! I worked on this project for the last six years with a leading role in the laser development, in particular with financial support from NFR (project PsCool). This result was awaited since 1988. It is a milestone in antimatter research opening the road for precision spectroscopy to test bound state Quantum Electro-Dynamics and the gravitational red-shift on antimatter. This achievement got a lot of attention in the media with several interviews in international press organs (Physics (APS), CERN, Ö1, Le Monde, Ansa, RAI, Titan.uio.no, WNP, BBC, PhysicsWorld, BBC news Mundo)
2023.10.03 Nobel prize in physics for attosecond science! Congratulations to Pierre Agostini, Anne L'Huillier and Ferenc Krausz. Read about it in Norwegian from forskning.no and titan.uio.no.
2023.09.27 The ALPHA collaboration at CERN measures that antihydrogen falls down! Read more about it in Norwegian and in English.
2023.09.14 AEgIS: the fall of antimatter. I am holding the physics department Felleskollokvium! Come and listen to what we know on antimatter at a general audience level.
2023.02.21 My PhD work on Quantum-Path Resolved Attosecond High-Harmonic Spectroscopy is now published in PRL with a viewpoint highlight. See the related article published in Titan.
2023.01.24 Research with the Ohio State University on the validity of the Kramers-Kronig relation in XUV attosecond transient absorption is now published in Optica. This work makes use of a phase grating element for stable XUV interferometry.
2023.01.23 The annual report of the AEgIS collaboration is online.
2022.08.05 A new inertial sensor developped in the AEgIS collaboration is presented in Measurement Science and Technology.
2022.01.13 The annual report of the AEgIS collaboration is online.
2021.08.18 The PhD work of Christian Zimmer on the possibility to laser cool positronium in a magetic field is now published in PRA.
2021.05.07 Morphologically tuned nanochanneled silicon targets developed by the AEgIS collaboration are reported to efficiently produce thermalized positronium in J. Phys. B.
2021.03.02 My PhD work on multidimentional XUV attosecond spectroscopy is doing the cover of the Optica 2021 March issue!
2021.02.08 We (the AEgIS collaboration based at CERN) report the first pulsed production of antihydrogren using a charge exchange reaction between Rydberg positronium and a cold plasma of antiprotons in Communications Physics.
2021.18.01 How long does it take a core excited ion to relax to its ground state? Our work at the LCLS X-ray free electron laser (X-FEL) on Clocking Auger electrons is now released in Nature Physics.
2021.11.01 The annual report of the AEgIS collaboration is online.
In the news
Han får 250.000 for utvikling av laser som kan kjøle antimaterie
Nobelprisvinner Anne L’Huillier jobbet alene som kvinne de første 17 årene av karrieren
Des lasers refroidissent une particule furtive mi-matière, mi-antimatière
Nytt antimaterie-resultat vekker begeistring
Matter-antimatter gas of positronium is laser cooled
Sensorer fra smarttelefoner fotograferer antimaterie på CERN.
Forskere vil lage et atom av antimaterie og materie – som ødelegger seg selv
Hvor kort tid er det mulig å måle noe?
2023 nobelpris i fysikk til attosekundfysikk
Ny forskning på antimaterie: – Det er et enormt resultat
Hvis epler faller nedover, faller da anti-epler oppover?
AEgIS on track to test free-fall of antimatter
Des impulsions d'atomes d'antihydrogène pour mesurer la gravité
Ora sappiamo quando gli atomi di antidrogeno vengono prodotti
Awards
- 2026 Tycho Jægers Prize in Electro-Optics.
- 2024: Top 10 Breakthroughs of the Year in physics for 2024 to the AEgIS collaboration at CERN, and Kosuke Yoshioka and colleagues at the University of Tokyo, for independently demonstrating laser cooling of positronium
- 2019: FRIPRO Young Research Talent grant (Laser cooling of positronium).
- 2014: EDOM PhD award (Multidimensionnal Phase Spectroscopy of the Attosecond Molecular Emission)
Positions held
- May 2020 - now: researcher, UiO (Oslo, Norway)
- Nov. 2019 - Apr. 2020: MSCA visiting scholar, UiO (Oslo, Norway)
- May 2017 - Oct. 2019: COFUND fellow, AEgIS, CERN (Meyrin, Switzerland)
- Feb. 2014 - April. 2017: postdoctoral stay, in the Agostini-DiMauro group, OSU (Columbus, OH, USA)
- Sept. 2020 - Jan.2014: PhD, CEA-Saclay (Saclay, France)