Quantum breakthrough without magnets: Lithuanian physicists have found a way to "program" atoms with light
A group of researchers from the Faculty of Physics at Vilnius University has presented a theoretical model that allows "programming" atoms using light, completely eliminating the need for external magnetic fields. This radically simplifies the architecture of quantum systems and opens new horizons for information processing.
The essence of the approach is as follows: a light beam first sets the atoms to a specific state, and then this prepared medium alters the shape and polarization of complex laser beams. The key element of the model is optical vortices. These are beams with a spiral wavefront structure, where the intensity drops to zero at the center. The size of this dark region is determined by the topological charge—a value that can take any integer, both positive and negative.
From Qubits to Qudits: 10,000 States Instead of Two
In practice, this means the ability to encode information not in binary qubits, but in qudits—multi-level units of quantum information. A single qudit can contain up to 10,000 different states, exponentially increasing the computational power and memory capacity of quantum systems.
To control vector vortices, the scientists modeled the interaction of the beam with an atomic gas, where the atoms have three energy levels. In such a model, the prepared medium "inherits" the spatial pattern of the light: in some zones, atoms actively absorb radiation, while in others they become nearly transparent. A feedback loop emerges—the atomic response reshapes the beam itself. Instead of a simple ring, a complex petal-like pattern forms with several bright regions around the center, and the polarization structure is completely transformed.
Previously, such control required powerful external magnetic fields and bulky equipment. The new model eliminates this need, making the system more compact, energy-efficient, and cost-effective.
Practical Prospects
In theory, this development paves the way for creating faster quantum processors, highly secure quantum communication networks, and ultra-precise optical sensors. Eliminating magnetic fields removes one of the main limitations of modern quantum systems—their sensitivity to external interference.
Expert Opinion: This is an elegant solution that shifts quantum control from the realm of complex engineering challenges to purely optical manipulations. If the model is confirmed experimentally, we will witness a paradigm shift in quantum chip design—from bulky magnetic systems to compact photonic circuits.