A Novel Atom-Twisting Method Proposed by ITMO Researchers

Unlike that of ordinary atoms, the wavefront of twisted atoms resembles a meat grinder screw or corkscrew helix, which makes them a promising means of analysis of material structure in electron microscopy and data transmission. 

Typically, the “twist” is achieved via custom diffraction gratings through which researchers run a stream of particles. The problem is, though, that the higher the particle energy is, the smaller the grating should be. Therefore, the method grows difficult to implement on modern-day particle and ion accelerators. 

To that end, researchers from ITMO University suggested a brand-new method that can make the process easier and faster. As a starting point, the team calculated how the wave function of a photon, i.e. its twisted structure, interacts with an electron in a hydrogen-like atom. The experiment showed that an atom gains the twisted state of a photon when the latter is absorbed.

“Given that the quantum state of light is a form of data, it should be preserved loss-free in case of any light-system interaction. We found that if this information cannot be transferred to an electron directly, practically all data stored in a photon goes to the center of an atom’s mass. Our finding may cast some light on how different conservation laws work for structured light; for instance, how the quantum state of light transforms when an electron absorbs a photon in a trapped atom or how a twisted state transfers from a photon to an electron when leaving the matter,” says Stanislav Baturin, an author of the paper and a senior researcher at the Faculty of Physics. 

The team intends to test their theory in practice via particle accelerators or special spectroscopy facilities. As the calculations demonstrated, some particles in a stream of atoms  gain a twisted structure under the influence of a laser beam; the laser will require minimal modifications for the test. 

The new approach allows for a quick and simple twisting of atoms for further study, as well as paves the way for a systematic description of composite twisted particles. In the future, the team wants to adapt the method to other twisted particles and complex objects, such as protons.