Listening to quantum beats could reveal rhythm of birds’ migratory compass

A method to detect quantum beats – extremely short-lived oscillations between spin states in a radical pair – has been invented by researchers in Germany and Russia. Being able to observe quantum oscillations directly could help scientists unravel how a migratory bird’s magnetic compass works, which is believed to be based on a radical pair mechanism.

A radical pair is a system, two molecules for example, with two unpaired electrons. Electrons behave like microscopic magnets, possessing a quantum mechanical property known as spin that gives them a magnetic moment. The spins of two unpaired electrons can be either antiparallel (singlet) or parallel (triplet) to one another.