Personal Page of Remi Geiger


Researcher ID: M-4231-2016                

                                                                                                                                                                        
Contact:
Dr. Remi GEIGER Assistant Professor Université Pierre et Marie Curie SYRTE - Observatoire de Paris 77, avenue Denfert-Rochereau F-75014 Paris Tel: +33(0)1.40.51.22.08 Fax: +33(0)1.43.25.55.42 Email : remi(DOT)geiger(AT)obspm(DOT)fr Website : https://syrte.obspm.fr/spip/science/iaci/          
Long-term internship (6 month or 1 year) position available : development of an optical cavity for atom interferometry                                                                                                                                                                                     
Current research interests
  • Matter-wave interferometry
  • Inertial sensors
  • Tests of Gravitation
  • Gravitational wave detection
  • Quantum metrology
  • Instrumentation
Past research interests
  • Non-equilibrium dynamics and thermalization in isolated quantum many-body systems
  • One-dimensional quantum gases
  • Atom-chips

Current research at SYRTE, Paris Observatory


I am currently supervising two projects at the SYRTE laboratory : 


- the realization of the cold atom sources for the Matter wave laser Interferometric Antenna (MIGA) instrument.

See the webpage of the Atom Interferometry and Inertial Sensor team for more details on each project.

For a general audience presentation of the MIGA project, you can click on this link.


Institutional and Research responsibilities


Co-coordinator of the 'Gravitation and Fundamental Physics' (GPhys) programme of Paris Observatory (see this link)

Co-coordinator of the "detector developments" working group of the French Gravitational Wave network


Publications
See the Publication tab.

Short CV
  • Since Sept. 2013 : Assistant Professor (Maître de Conférence) at SYRTE, Université Pierre et Marie Curie, Paris, France
  • 2011-2013 : postdoc in the atomchip group of Jörg Schmiedmayer, Atominstitut/TU-Wien, Austria (Lise-Meitner Fellow of the Austrian Research Foundation - FWF)
  • 2008-2011: PhD thesis in the group of Alain Aspect and Philippe Bouyer at Laboratoire Charles Fabry, Institut d'Optique, Université Paris Sud, France
  • 2007-2008: Master in Physics in the group of Sabine Klapp, Institut für Theoretische Physik, Technische Universität Berlin, Germany
  • 2005-2008: Engineering and Physics studies at Ecole Supérieure d'Electricité (Supélec), France
  • 2003-2005: Physics and Mathematics studies at Lycée Pasteur, France

Prizes and distinctions
  • 2015: laureate of the Edouard Branly/IEEE France prize for young reserchers in Physical Sciences 
  • 2014: laureate of the Emergence call from the city of Paris (project HSENS-MWGRAV, 240 k€ funding)
  • 2012: laureate of the ParisTechdoctoral thesis prize
  • 2011: Lise Meitner Fellowship of the Austrian Science Fund (project FWF-LM1423)
  • 2010: Young researcher prize of Centre National d'Études Spatiales (CNES)
  • 2010: Prize of the EDOM doctoral school of Université Paris Sud
  • 2008: Three year research grant from CNES
  • 2008: Éleuthère Mascart medal of Supélec.


Past research

I. Postdoc in Vienna (2011-2013): non equilibrium dynamics of isolated quantum many body systems. Investigations on the KRb experiment in the atomchip group.

II. PhD thesis (2008-2011): Airborne matter wave inertial sensor 
Laboratoire Charles Fabry, Institut d'Optique, France 


- Short description: Our work aims at developing an atom accelerometer involving two different atomic species (87Rb and 39K) and operating in a plane which carries out parabolic fights. The physical process underlying the operation of our instrument is a matter wave interferometer using bosonic atoms which are laser cooled down to temperatures of the order of the micro Kelvin. So far, we have operated the first airplane based cold atom inertial sensor and achieved acceleration sensitivity of the order of tens of micro-g in one second. We have also demonstrated that we improve the sensor sensitivity in micro-gravity and have investigated original atom interferometer geometries to reject the vibration noise of the plane. Then, we have developed laser sources to cool 39K atoms and started to implement the K-interferometer. In the future, we plan to test the Universality of Free Fall (Weak Equivalence Principle) with atom interferometry by comparing the acceleration of Rb and K atoms. In this respect, it may be possible to increase significantly the interferometer interrogation time and the sensitivity of the test in weightlessness.
 - Key words: Cold atoms, atom interferometry, micro-gravity, inertial sensor, Equivalence Principle.
[Manuscript] (in French)


III. Diploma thesis (2008) Long-range order in quasi two-dimensional dipolar fluids: a Density Functional Theory study 
Institut für Theoretische Physik, Technische Universität Berlin (supervision of Prof. Dr. Sabine Klapp)

Short description: During my stay in Berlin, I investigated the phase behavior of dipolar fluids when they are confined in two-dimensions. Dipolar fluids are composed of particles carrying a permanent dipole moment and thus interact with each other through long range and anisotropic interactions. A particularly interesting class of dipolar fluids are ferrofluids (or magnetic liquids), which are colloidal suspensions of small (~10 nm) ferromagnetic particles with a strong dipole moment. Their interesting hydrodynamic properties in the presence of external magnetic fields make them interesting for many applications in electronics, mechanical engineering or medicine. 
Spatial confinement may have significant effects on the phase behavior of a fluid compared to its bulk counterpart. In this thesis, I explore the limiting case of two-dimensional dipolar fluids and describe the manifestation of macroscopic polarization depending on thermodynamic variables such as density, temperature or chemical potential.  
A statistical mechanics method called the Density Functional Theory is used with an appropriate ansatz for the interparticle correlations. In this way, the free energy functional of the system is derived as well as the dependance of the order parameters with the thermodynamic variables. Within the so-called "modified mean-field" approximation, the pair correlation function is approximated by a Boltzmann factor (low-density limit). While it simplifies the calculations, it provides a general overview of the phase diagram and of the leading order terms in the free energy. In the thesis, I highlight the dimensionality effects by comparing the 2D and 3D dipolar fluids.
Key words: Dipole-dipole interactions, dimensionality, phase diagram, density functional theory, correlations.
[Manuscript] (in English)