At a Glance
- A recent study has provided new insights into how light can still interact with matter even during destructive interference, challenging classical physics assumptions.
- Researchers proposed that classical interference patterns could be understood using quantum mechanics, with photons existing in bright or dark states rather than just as waves.
- Their experiments demonstrated that light in regions of destructive interference could still be described by entangled quantum states capable of interacting with matter.
- This new framework bridges the gap between classical and quantum physics, offering a more straightforward explanation for phenomena observed in experiments like the double-slit experiment.
- The findings open new opportunities for exploring light-matter interactions at the quantum level and advancing our understanding of hybrid quantum-classical systems.
One of the most fascinating concepts in physics is how light behaves as both a wave and a particle. For many years, classical physics theories suggested that when light waves interfere with each other destructively, canceling out their electric fields, they do not interact with matter. However, quantum mechanics, which focuses on the behavior of particles at the smallest scales, has suggested that light can still interact with matter even in these conditions. A recent study by a team of scientists from Germany, Brazil, and the United States sheds light on this issue, providing new insights into light-matter interactions.
The study, published in Physical Review Letters, focuses on a concept known as “classical interference,” which describes how light waves interact to produce patterns of bright and dark areas. Scientists have long believed that these interactions could only be explained using wave theory. However, this new research takes a different approach. The researchers proposed that classical interference could also be understood in terms of quantum particles—specifically, photons (light particles) that exist in either bright or dark states. They applied quantum mechanics principles to describe how these photons behave in ways classical physics could not fully explain.
The team used a new theoretical framework in their experiments that combined quantum optics and classical interference. The research showed that light waves could be described as a mixture of “bright” and “dark” quantum states, entangled particle superpositions. These states help explain why specific photons can still interact with matter, even if the average electric field of the light appears to cancel out. The team’s findings suggest that even in regions of destructive interference, where classical physics predicted no interaction, photons can still exist and affect their surroundings.
This new understanding challenges traditional views in physics and could lead to a better understanding of light behavior in quantum mechanics. The findings also offer a fresh perspective on experiments like the double-slit experiment, which has been at the heart of debates between particle and wave theories of light. The team’s work clarifies a long-standing scientific debate and could pave the way for future research on how quantum systems interact with classical systems.
References
- Villas-Boas, C. J., Máximo, C. E., Paulino, P. J., Bachelard, R. P., & Rempe, G. (2025). Bright and dark states of light: The quantum origin of classical interference. Physical Review Letters, 134(13), 133603. https://doi.org/10.1103/PhysRevLett.134.133603
- Fadelli, I. & Phys.org. (2025, April 25). New quantum optics theory proposes that classical interference arises from bright and dark states of light. Phys.Org; Phys.org. https://phys.org/news/2025-04-quantum-optics-theory-classical-bright.html
