SCIENTIFIC EDUCATIONAL CENTER science idea

Topological optics and topological photonics have become "hot" fields of science since the 1980s after singularities in magnetic fields were discovered. And the relatively recent Nobel Prize, awarded for the discovery and study of topological features in condensed matter physics, has further spurred the interest of the scientific community, because all this opens up prospects for the implementation of non-trivial types of interactions of electromagnetic waves with matter. This, in turn, can be used in a number of new technologies for the transmission of information and energy over long distances.

Not so long ago, a group of physicists from the UK and Singapore announced the discovery of a new "family" of electromagnetic pulses with a toroidal topology. These impulses are ideal physical embodiments of solutions to Maxwell's equations, which makes it possible to control their topological complexity and obtain the so-called supertoroidal topology. The electromagnetic fields of such supertoroidal pulses form structures that almost completely coincide with the structure of skyrmions, which under normal conditions are "vortices" of magnetic fields in the medium of some magnetic materials. Only here the skyrmions of supertoroidal pulses fly in space almost at the speed of light.

Skyrmions, complex topological quasiparticles, were discovered by Tony Skyrme in 1962 in an attempt to create a unified nucleon model. As mentioned above, skyrmions are nanoscale magnetic vortices with ordered structures. These quasiparticles have already been studied quite well in many condensed matter systems, including exotics, such as Bose-Einstein condensate, chiral magnets, superconductors and liquid crystals. But if Skyrmions can fly, it will open up an endless series of new possibilities for next-generation information devices.

The supertoroidal pulse, called by scientists a "flying donut", includes recursive toroidal topological structures, due to which the configuration of its electromagnetic field resembles a matryoshka doll. And the topological complexity of such a pulse can be controlled quite simply, increase or decrease the number of toroidal pulses embedded in it, adjust the direction of the magnetic vortex twisting, etc.

The topological features of supertoroidal pulses provide additional "degrees of freedom" that can be used as information carriers for optical encoding-decoding systems, measuring systems of various kinds, information display systems with ultra-high resolution and, of course, systems for wireless transmission of information and energy over long distances.

The article was published in the journal Nature Communications
PHOTO: Diagrams of spatial topological structures of magnetic vortex rings and skyrmions in a supertoroidal light pulse. Gray dots and rings mark the distribution of singularities (saddle points and vortex rings) in the magnetic field, large pink arrows mark the selective directions of magnetic vectors, and smaller colored arrows show skyrmion structures in the magnetic field © Yijie Shen

Source: dailytechinfo.org, sci-dig.ru