Photonic Momentum in bi-anisotropic media – PHOTONIMPULS

Magneto-electric media are photonic materials in which electrical polarization is not only induced by an applied electric field, but also by an external magnetic field. They are part of a much larger class of so-called bi-anisotropic media described by a more complex constitutive equation , relating microscopic and macrocopic electromagnetic fields. Examples considered in this proposal are moving dielectric media (where the ``Fizeau effect'' or ``Fresnel drag' is equivalent to magneto-electric behaviour in the optical constants), magneto-chiral media (where the simultaneous action of natural and magnetic circular dichroïsm induces bi-anisotropic behaviour) and media exposed to strong electric and magnetic fields. Bi-anisotropic media have become into fashion because of their very special features. One was put forward in 2004: electromagnetic zero-point fluctuations seem to achieve a net momentum density. The popular press was talking about 'momentum from nothing' (APS focus) The central point of our proposal is that in bi-anisotropic media, isotropic electromagnetic fields achieve a finite momentum density, which can be transferred to matter. The fascinating possibility to have momentum of electromagnetic zero-point fluctuations ' baptized 'Casimir momentum' - is a special case. This concept raises many theoretical problems, such as the catastrophe at high frequencies, and the possible violation of Lorentz-invariance. If our predictions are correct, a chiral object, when subjected to a magnetic field, will start moving along the field lines. This has never been observed, and will have many applications in photo-chemistry. The present proposal has a theoretical part (LPMMC-Grenoble) and an experimental part (LNCMP-Toulouse). Theory has progressed slowly but too many elements lack experimental confirmation. It has become urgent to start experiments on 'delicate issues' in the theory. The basic problem that we address is the exchange of momentum between magneto-electric matter and electromagnetic fields. Among the delicate issues we mention the cut-off procedure to get rid of the UV catastrophe of zero-point motion (an experiment is proposed), the longstanding Abraham-Minkowski controversy about what part of the total momentum is due to matter and what part due to radiation (an experiment is proposed), and the subtle role of chiral structure in transfer of momentum to (thermal) photons. We intend to launch a new experimental project baptized 'magnetochirodynamics' . One fascinating question is whether it is possible to separate opposite enantiomeres (by giving them opposite speeds) using just a magnetic field and isotropic radiation, as once proposed by Pasteur. The first theory is planned and a clear proposal for an experimental realization should be ready by the end of the 3 year project. At the same time we will pursue theoretical efforts to understand radiation momentum in a microscopic, fully quantum-mechanical picture, i.e. both matter and radiation are treated quantum-mechanically. We hope that the full quantum theory gives a finite result, that is much smaller then the theoretical predictions by Dr. Feigel. At the same time we have to modify this theory for optical dispersion and absorption in order to confront it with our experimental test. We launch a very closely related study on the mass of Casimir energy. This study will involve no experimental activity., but establishes a crucial link of our projetc with other theoretical approaches on inertial mass of vacuum energy. This proposal concerns an entirely new subject with controversial aspects, and sometimes modest literature, and no experiments. This is why we belief that ANR blanc support is justified. The 2004 article by Dr. Feigel did not get a follow-up, yet received two Comments in PRL. Today, only 5 articles exist. Also our work has been commented in Physical Review Letters (2008). The subject is part of the much broader study of Casimir forces and Casimir energy, which is undoubtedly one of the most exiting elements in today's research, and too which we have to make contact. Casimir forces are important on the nano-scale, at the same time Casimir energy is believed to play a crucial role in the cosmological constant puzzle. All across the world Casimir forces are the subject of both applied research (e.g. the proximity force approximation or optical path approximations to calculate Casimir forces between arbitrary objects, and the connection to Van de Waals forces to go beyond this approximation, and studies on more fundamental issues. We believe that the present proposal is in principal 'fundamental', yet with a very high potential to become applied in a near future. We hope that the high risk factor and the novelty of this proposal are appreciated in the evaluation. We believe that a high risk project can be confided to a collaboration that has shown to be original and successful for more than a decennium.