Spooky Action at a Distance

Physicists from The City College of New York (CCNY) have found that beams from typical laser pointers are able to mimic quantum entanglement. Quantum entanglement is when two quantum particles that are separated by a great distance become an entangled system and share a quantum state. Plainly stated, when one of these particles is touched, its entangled pair can feel it. PhD student Giovanni Milione said that “At the heart of quantum entanglement is ‘nonseparability’ – two entangled things are described by an unfactorizable equation. Interestingly, a conventional laser beam (a laser pointer)’s shape and polarization can also be nonseparable.”

Simple Lasers

Milione and his team transformed the laser’s beam into a polarization-dependent shape that they call a vector beam to make its shape and polarization nonseparable. The found that “touching” the vector beam’s polarization encoded two bits of information, which is double the amount that would be encoded had the beam been separable. CCNY Distinguished Professor of Physics Robert Alfano said that “In principal, this could be used to double the data speed of laser communication. While there’s no ‘spooky action at a distance,’ it’s amazing that quantum entanglement aspects can be mimicked by something that simple.”


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