A quantum breakthrough without magnets: how light programs atoms for next-generation computing
Physicists from Vilnius University have presented a theoretical model that radically changes the approach to controlling quantum systems. Instead of bulky external magnetic fields, they propose using light to pre-"program" atoms. This is not just a laboratory curiosity—it is a potential foundation for next-generation quantum computers and communication networks.
Optical Vortices and Encoding in Qudits
The model is based on optical vortices—laser beams with a spiral wavefront structure. In their "core," intensity drops to zero, and the size of this dark region is determined by the topological charge. A key feature: this charge can take any integer value—both positive and negative. In practice, this means the ability to generate up to 10,000 different states. Instead of the familiar qubits, which operate with two states, we gain access to qudits—multi-level units of quantum information, exponentially increasing computational power.
How Light Reprograms the Medium
The researchers simulated the interaction of a vector vortex beam with an atomic gas, where each atom has three energy levels. The light first "writes" its spatial structure into the medium: in some zones, atoms begin to actively absorb radiation, while in others, they become almost transparent. Then, a feedback effect occurs—the atomic response begins to reshape the beam itself. Instead of a simple ring, a complex petal-like pattern with several bright regions emerges, and the polarization structure is completely transformed. Previously, such control required powerful magnets and complex equipment.
Practical Prospects
Theoretically, this development paves the way for creating faster quantum processors, highly secure quantum communication networks, and ultra-precise optical sensors. Notably, just a few days ago, Sandia National Laboratories and Quantinuum published data on their 98-qubit quantum computer, Helios. However, the approach using light to program atoms without magnetic fields may prove to be more scalable and less costly to implement.
My Expert Assessment: This method addresses one of the main problems of quantum systems—the need for complex and expensive magnetic isolation. If the model is confirmed experimentally, we will witness a paradigm shift: from "iron" control to "light" programming of quantum states. Qudits with 10,000 levels are not just a step forward—they are a leap into a new dimension of computational complexity.