A team of physicists has just modeled an astonishing quantum phenomenon where ultra-powerful lasers generate light from vacuum. This work could soon be experimentally validated thanks to a new generation of laser facilities.
In quantum physics, vacuum is never completely inert. It is the seat of incessant fluctuations, where pairs of virtual particles appear and disappear in a fraction of a second. Researchers from the University of Oxford and Instituto Superior Técnico in Lisbon have simulated how intense laser beams can disturb this vacuum and produce light.
A quantum phenomenon finally visualized
Theory had long predicted that three crossed laser beams could polarize the vacuum's virtual particles, generating a fourth beam. This process, called four-wave mixing, has just been modeled in 3D and in real time. The simulations reveal how photons interact, like billiard balls, under the effect of electromagnetic fields.
Using the OSIRIS software, researchers were able to observe previously inaccessible details, such as the influence of laser asymmetry or the temporal evolution of interactions. These results, published in
Communications Physics, provide a solid foundation for future experiments.
The simulations also show subtle effects, like vacuum birefringence, where light polarization is modified by extreme magnetic fields. These predictions could be tested in the coming years.
Toward experimental confirmation
Several cutting-edge laser facilities, like Vulcan 20-20 in the UK or the Extreme Light Infrastructure in Europe, now reach the power levels needed to observe these phenomena. These lasers will help verify whether vacuum can indeed produce light under certain conditions.
The models developed by the team will serve to optimize experimental parameters, such as laser pulse shapes or their synchronization. This data is essential for detecting faint signals, like photon-photon scattering, which has never been directly observed.
Beyond validating quantum theories, this work could help track hypothetical particles like axions, potential candidates for dark matter. The simulations thus open new avenues for exploring fundamental physics.
Article author: Cédric DEPOND