Physicists looking for a way to test their theory about strings might make more progress if they tangle them up.
String theory — equations that aspire to explain all of nature’s particles and forces — has extended its reach to the strange quantum behavior known as entanglement, physicists report September 2 in Physical Review Letters. Repurposing string theory mathematics allowed physicists to solve a hard problem involving entanglement, a strange feature at the heart of quantum mechanics. In doing so, the new study also points out a way to test whether the co-opted string theory equations are actually correct.
“String theory has not had a lot of success in making falsifiable predictions,” says study coauthor Michael Duff of Imperial College London. “But in the field of quantum information theory, it can.”
One of the hallmarks of quantum information is that particles carrying it can interact in a way that makes them “entangled,” so that measuring one seems to instantaneously affect the other, even at great distances. Over the last few years, Duff and his colleagues began to notice similarities between string theory — the idea that particles of matter and force are tiny vibrating loops or strands — and the equations that govern entangled particles.