Quantum entanglement, a phenomenon studied by Einstein, Podolsky, and Rosen in 1935, challenges our classical understanding of physics. It allows two particles to remain connected regardless of the distance separating them, without any visible exchange of information. This property, dubbed "spooky action at a distance" by Einstein, is now at the heart of quantum technologies.
Conversion of two photons into an entangled state in their total angular momentum within a nanoscale system.
Credit: Shalom Buberman, Shultzo3d
Photons, particles of light, can exhibit quantum entanglement through various properties such as their frequency or polarization. However, in structures smaller than their wavelength, these properties merge into a single one: total angular momentum. This discovery paves the way for new applications in nanophotonics.
The Technion team, led by Amit Kam and Shai Tsesses, published their findings in
Nature. They successfully entangled photons in nanoscale systems, not through their usual properties, but through their total angular momentum. This entanglement was confirmed by a series of precise measurements.
This discovery marks the first new form of quantum entanglement identified in over twenty years. It could enable the design of more compact and efficient quantum components, essential for future quantum communication and computing technologies.
The researchers also mapped the quantum states of photons in these nanoscale systems. This mapping is crucial for fully understanding and harnessing the potential of this new form of entanglement for technological applications.
What is quantum entanglement?
Quantum entanglement is a phenomenon where two particles become so closely linked that the state of one instantly influences the other, no matter the distance between them. This concept, initially criticized by Einstein, is now a cornerstone of quantum physics.
Unlike classical interactions, entanglement does not require a mediating force or field. It relies on the probabilistic laws of quantum mechanics, offering unprecedented possibilities for technology.
The discovery of new forms of entanglement, such as total angular momentum, further expands the potential applications, particularly in the miniaturization of quantum devices.