In 1978, a team of German researchers proposed that migratory songbirds use a quantum compass based on radical pair species, which are pairs of molecules linked by a covalent bond that can be broken by the absorption of light. Breaking this bond results in an electron transfer between the two molecules and the creation of a radical pair.
The radical pair compass model is supported by a number of experimental studies but it is not yet fully understood how the compass works at a molecular level. The new approach, developed by researchers at the University of Oxford, could help to fill in these gaps.
The researchers' model incorporates radical pair analysis into a more general model of bird navigation and the results suggest that radical pairs could indeed be used to detect the direction of the magnetic field by exploiting a quantum phenomenon known as spin entanglement.
The ability to sense magnetic fields is called magnetoreception and it is found in a wide variety of animals including birds, fish, insects and amphibians. Magnetoreception is thought to be an important navigational tool for many animals and helps them to find their way over long distances.
Birds such as the European robin, use a combination of magnetoreception and other sensory cues such as the sun and stars to navigate when migrating. The new study could help to further understand magnetoreception in birds and other animals.
The study also highlights the potential application of quantum physics in biology and other areas outside of physics.
