An overdose of the spooky connection can break down quantum computing systems, researchers find
Physicists have long thought that quantum entanglement, a mysterious link between separated particles that Einstein called “spooky action at a distance,” would allow quantum computers to solve certain hard math problems much faster than ordinary computers. But now it seems that entanglement can also be a nuisance.
Instead of speeding up the process, too much entanglement can break down the entire system, researchers report in a paper to appear in Physical Review Letters.
Entanglement occurs when quantum particles of energy or matter — such as atoms, ions or photons — interact, becoming intimately connected regardless of how far apart they later become. When two objects are entangled, their properties are mutually related.
“Consider two atoms,” says David Gross of Technical University of Braunschweig in Germany, lead author of the new paper. “We can think of a particle like an atom with tags identifying its p