Researchers at Technion have discovered a new form of quantum entanglement involving the total angular momentum of photons confined in nanoscale structures.
This marks the first discovery of a new quantum entanglement mechanism in over two decades and could revolutionize the development and miniaturization of quantum communication and computing technologies.
Quantum entanglement, a phenomenon that Albert Einstein famously described as “spooky action at a distance,” has perplexed physicists since its theoretical introduction in 1935. Einstein, along with Boris Podolsky and Nathan Rosen (who later established Technion’s Faculty of Physics), published the seminal EPR paper that first explored the concept.
The phenomenon challenged conventional understanding by suggesting that measuring one particle could instantaneously affect another particle’s state regardless of the distance separating them, seemingly defying the limits of information transfer.
Despite Einstein’s skepticism, quantum entanglement has since been proven to exist and has formed the foundation for revolutionary technologies. Technion’s Research Professor Asher Peres, working with colleagues Charles Bennett and Gilles Brassard, demonstrated that this property could enable quantum teleportation – the cornerstone of modern quantum communication.
The significance of quantum entanglement was formally recognized when the 2022 Nobel Prize in Physics was awarded to Professors Alain Aspect and Anton Zeilinger (both Technion honorary doctorate recipients) and John Clauser for their experiments on quantum entanglement.
The new research, published in Nature, was conducted by a team led by Ph.D. student Amit Kam and Dr. Shai Tsesses. Their work revealed that photons-particles of light-can be entangled within nanoscale systems approximately one-thousandth the width of a human hair.
What makes this discovery particularly significant is that the entanglement occurs through the total angular momentum of photons, rather than through conventional properties such as spin or trajectory that characterize previously known forms of quantum entanglement.
“When photons are confined to structures smaller than their wavelength, we discover that it becomes impossible to separate different rotational properties,” explained the researchers.
“The photon is then characterized by a single quantity-the total angular momentum.”
The ability to entangle photons at the nanoscale offers two major advantages. First, it enables significant miniaturization of quantum devices, potentially allowing more operations to be performed in smaller spaces-similar to how electronic circuits have been miniaturized over time.
Perhaps more importantly, this nanoscale confinement intensifies the interaction between photons and the surrounding materials, unlocking phenomena and applications that aren’t possible with photons at conventional scales.
Through a series of precise measurements, the Technion team mapped the unique quantum states that emerge when photons enter and exit nanoscale systems. They successfully entangled these states using properties unique to nanoscale environments and confirmed the quantum correlation between photon pairs that definitively indicates entanglement.
This discovery could lead to the development of new tools for designing quantum communication and computing components based on photons, with significantly reduced size requirements. The research opens new possibilities for quantum technologies that could operate at previously unattainable scales.
“This is the first discovery of a new quantum entanglement mechanism in more than 20 years,” noted the researchers. “It represents a fundamental advancement in our understanding of how quantum properties manifest at the nanoscale.”
