Quantum breakthrough from Lithuania: light 'programs' atoms without magnetic fields
Physicists from Vilnius University have presented a theoretical model that fundamentally changes the approach to controlling quantum systems. Instead of cumbersome external magnetic fields, the researchers propose using light to pre-"program" atoms. This method could simplify the creation of next-generation quantum processors and communication networks.
Optical Vortices as a Basis for Control
The model is based on optical vortices—laser beams with a spiral wavefront structure. At their center, intensity drops to zero, forming a dark region. The size of this region is determined by the topological charge, which can take any integer value—both positive and negative. In practice, this allows creating up to 10,000 different states, encoding information in qudits—multidimensional quantum units that surpass standard qubits in capacity.
Operating Principle: Light and Atomic Gas
The researchers simulated the interaction of a vector vortex beam with an atomic gas having three energy levels. The light first "programs" the atoms: in some regions, they intensely absorb radiation; in others, they become almost transparent. Then feedback begins—the prepared atomic medium changes the shape and polarization of the laser beam itself. Instead of a simple ring structure, a complex petal pattern emerges with several bright regions around the center. Such polarization control previously required powerful magnetic fields and complex equipment.
Practical Prospects
Theoretically, this development paves the way for faster quantum processors, highly secure quantum communication networks, and ultra-precise optical sensors. Eliminating external magnetic fields reduces energy consumption and simplifies device design.
My Expert Opinion: This model demonstrates an elegant way to solve one of the key problems in quantum technologies—scaling. If experiments confirm the theory, we will gain a cheap and compact method for controlling qudits, which could accelerate the commercialization of quantum networks by years.