The University of Massachusetts Amherst
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Hardware Security

Disproving Einstein: the Phenomenon of Quantum Entanglement and Implications of Quantum Computing

Quantum-Entanglement

Albert Einstein famously disparaged quantum entanglement as “spooky action at a distance,” because the idea that two particles separated by light-years could become “entangled” and instantaneously affect one another was counter to classical physics and intuitive reasoning. All fundamental particles have a property called spin, angular momentum and orientation in space. When measuring spin, either the measurement direction is aligned with the spin of a particle -classified as spin up- or the measurement is opposite the spin of the particle -classified as spin down. If the particle spin is vertical but we measure it horizontally the result is a 50/50 chance of being measured spin up or spin down. Likewise, different angles produce different probabilities of obtaining spin up or spin down particles. Total angular momentum of the universe must stay constant, and therefore in terms of entangled particles, they must have opposite spins when measured in the same direction. Einstein’s theory of relativity was centered around the idea that nothing can move faster than the speed of light, but somehow, these particles appeared to be communicating instantaneously to ensure opposite spin. He surmised that all particles were created with a definite spin regardless of the direction they were measured in, but this theory proved to be wrong. Quantum entanglement is not science fiction; it is a real phenomenon which will fundamentally shape the future of teleportation and computing.