In a new study, researchers have demonstrated that classical light systems can host previously undetected quantum behaviors, challenging our understanding of the boundary between classical and quantum physics. By fragmenting pseudothermal light fields into their multiparticle components, the team uncovered distinct quantum signatures within what was traditionally considered a purely classical system.
Published in PhotoniX | Estimated reading time: 4 minutes
For decades, scientists have sought to understand where classical physics ends and quantum mechanics begins. Now, researchers led by Chenglong You at Louisiana State University have made a remarkable discovery: classical thermal light fields can contain isolated quantum subsystems that exhibit surprising quantum properties.
The research team discovered that while most of the isolated multiphoton subsystems displayed classical behavior, some revealed striking quantum coherence properties that contrasted sharply with their classical host system. As stated in their paper, “the quantum dynamics within the pseudothermal system are overshadowed by the classical coherence properties of the majority of the constituent multiphoton subsystems.”
Using an innovative experimental setup, the team analyzed systems containing up to forty interacting particles. They employed a sophisticated detection method called photon-number-resolving (PNR) detection, which allowed them to collapse the state of scattered random optical systems into isolated multiparticle subsystems exhibiting distinct quantum dynamics.
One of the most surprising findings was that certain multiparticle subsystems produced interference patterns previously thought to occur only in entangled optical systems. This discovery suggests that quantum properties might be more prevalent in classical systems than previously believed.
“Our observations reveal the dramatic role that classical and quantum coherence has in the behavior of multiparticle systems,” the researchers note in their findings. This work could have significant implications for developing more robust quantum technologies and understanding fundamental physics across multiple disciplines.
Glossary
- Pseudothermal Light Field
- A classical random optical system that contains multiple independent light waves with randomly modulated phases.
- Quantum Coherence
- A quantum mechanical property that describes the ability of quantum states to maintain specific phase relationships and exhibit interference effects.
- Orbital Angular Momentum (OAM)
- A property of light beams that describes their spiral flow of energy and angular momentum around their propagation axis.
Test Your Knowledge
How many particles were the researchers able to analyze in their quantum subsystems?
The researchers were able to analyze systems containing up to forty interacting particles.
What type of light field was used in this research?
The researchers used a pseudothermal light field, which is a classical random optical system containing multiple independent light waves with randomly modulated phases.
What detection method was crucial for isolating the quantum subsystems?
The researchers used photon-number-resolving (PNR) detection to collapse the state of scattered random optical systems into isolated multiparticle subsystems.
What unexpected quantum behavior did some of the isolated subsystems exhibit?
Some isolated subsystems produced interference patterns that were previously thought to occur only in entangled optical systems, demonstrating unexpected quantum properties within a classical system.
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