Quantum breakthrough without magnets: light "programs" atoms to create up to 10,000 states
Physicists from Vilnius University have presented a theoretical model that fundamentally changes the approach to controlling quantum systems. Instead of the traditional use of external magnetic fields, the researchers propose "programming" atoms using structured light. This discovery could become the foundation for the next generation of quantum computing devices and secure communications.
The essence of the method lies in a two-stage process: first, a light beam assigns a specific configuration to the atoms, and then this pre-prepared atomic medium actively alters the shape and polarization of the laser beams. The key element of the model is optical vortices—beams with a spiral wavefront, where the intensity drops to zero at the center. The size of this dark zone is determined by the topological charge, which, as the developers emphasize, can take any integer value—both positive and negative.
The practical significance of this concept is immense: using 10,000 different states, information can be encoded in qudits—multidimensional analogs of qubits. This multiplies the amount of data that can be processed or transmitted in a single cycle compared to the binary system of qubits.
To demonstrate the control of vector vortices, scientists simulated the interaction of a beam with an atomic gas having three energy levels. In this model, the prepared medium "inherits" the spatial pattern of light: in some areas, atoms actively absorb radiation, while in others they become almost transparent. A feedback loop emerges—the atomic response restructures the beam itself, transforming it from a simple ring structure into a complex petal pattern with several bright regions around the center. At the same time, the polarization structure of the beam also changes.
Previously, such control required powerful external magnetic fields and bulky setups. The new model promises to simplify the equipment and speed up the operation of quantum processors, as well as pave the way for ultra-precise optical sensors and highly secure quantum networks.
Analytical Commentary: Abandoning magnetic fields is not just a technical simplification but a paradigm shift. Magnetic fields create interference and limit the scalability of quantum systems. If this model finds experimental confirmation, we may witness a transition from laboratory prototypes to industrial quantum chips controlled solely by light. It is precisely such breakthroughs in fundamental physics that often become triggers for commercial adoption.