Without magnets and complex equipment: Lithuanian scientists have found a way to 'program' atoms with light
A group of researchers from the Faculty of Physics at Vilnius University has proposed a theoretical model that allows "programming" atoms using light, completely eliminating external magnetic fields. This is a fundamentally new approach to controlling quantum systems that could simplify the creation of quantum devices.
The essence of the method is that light first sets atoms to a specific state—"programming" them—and then this pre-prepared atomic medium alters the shape and polarization of complex laser beams. A key role in the model is played by optical vortices—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 so-called topological charge, which can take any integer value—both positive and negative.
In practice, this means we can achieve up to 10,000 different states. Instead of conventional qubits, which operate with two states, it becomes possible to encode information in qudits—multilevel units of quantum information. This represents a colossal leap in computational capacity and stability.
To control vector vortices, the scientists simulated the interaction of a laser beam with an atomic gas, where the atoms have three energy levels. In such a system, the prepared medium "inherits" the spatial pattern of light: in some areas, atoms strongly 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 appears with several bright regions around the center, and the polarization structure of the beam changes dramatically.
Previously, such control required powerful external magnetic fields and bulky equipment. The new model promises to free quantum systems from these limitations.
Theoretically, this development paves the way for faster quantum processors, highly secure quantum communication networks, and ultra-precise optical sensors. While the industry is still grappling with scaling qubit systems, such fundamental breakthroughs in quantum state control are exactly what will take us beyond current capabilities.
Expert comment: Eliminating magnetic fields in quantum control is not just a technical simplification. It removes one of the main barriers to commercially viable quantum systems. If the model is confirmed in practice, we could see a fundamentally new class of compact quantum devices operating on optical tables rather than in cryogenic chambers.