On January 28, 2025, researchers from the National Institute of Standards and Technology (NIST) unveiled a novel approach to studying the interaction between atoms and light, a discovery poised to enhance the development of stable quantum systems. This advancement holds significant implications for quantum technologies, including rapid computing and secure communication.
The interaction between atoms and light is fundamental to the behavior of the physical world, yet remains complex to understand and control. The recent study focused on these interactions within multi-level atomic systems, potentially leading to the creation of stable quantum states.
Traditionally, scientists simplify models by treating atoms as two-level systems: ground and excited states. However, real atoms can possess multiple energy levels, complicating system dynamics. The research team, led by Ana Maria Rey from the University of Colorado Boulder and James Thompson from NIST, investigated atom-light interactions in systems featuring four energy levels.
Using strontium atoms arranged in one-dimensional and two-dimensional crystal lattices, the researchers concentrated on metastable energy levels, where atoms can reside for extended periods, allowing entangled states to persist even after the laser is turned off. James Thompson noted, "We plan to create conditions in our lab to transition atoms to an excited state that exists for a very long time, enabling a strong and programmable interaction between atoms. This will utilize a 2.9-micron wavelength transition, significantly larger than the distance between atoms in an optical lattice."
The team also developed a model to describe the system's dynamics. Future investigations aim to explore more complex multi-level systems, such as strontium atoms with up to ten ground and excited levels. This exploration could pave the way for programmable quantum systems and the distribution of entanglement.
As co-author Sanaa Agarwal stated, "We are approaching systems that can stably maintain entanglement, a crucial step for future quantum technologies."