We can routinely find examples of devices based on Coulomb forces accelerating particles under the influence of an electric field, even daily. However, this is not the same when considering particles experiencing a force proportional to a constant, external magnetic field, where one can only find a few exotic examples. The origin lies in the absence of magnetic monopoles, that has led researchers to consider more elaborated options such as quasiparticles generated on spin ices. In a recent PRL (editors’ suggestion), researchers from IFIMAC, IMN-CNM and ICMM have considered a different scenario, not based on condensed matter spin lattices, where a particle may be propelled by a magnetic field just like a magnetic charge (monopole) will do. The approach is based on two main ingredients: an isotropic radiation spinning (random) field and the magneto-optical effect. Isotropic and fluctuating electromagnetic fields have recently received lots of attention due to the plethora of phenomena occurring in optical binding forces induced by random fields. However, the consequences arising from the helicity value of the random field have never been considered. Driven by this reasoning, the researchers have analyzed the force induced by an isotropic and fluctuating radiation field with a well-defined helicity over a magneto-optical particle. The outcome is the existence of a force directly proportional to the magnetic field, and that the helicity of the random field is correspondingly transferred to the equivalent magnetic charge of the magneto-optical particle. With this study, the researchers demonstrate the existence of an alternative scenario where Coulomb forces on a single particle are induced by the magnetic field. The study is based on a completely alternative approach that does not rely on lattice condensed matter physics. The scenario considers the opto-mechanical effect of isotropic radiation fields with well-defined helicity on magneto-optical particles. [Full article]
