There's a type of particle called a Majorana fermion that was hypothesized in 1937. This particle has some unique properties, and it's long been theorized that Majorana particles could prove useful for quantum computing.

Microsoft has long been working on an alternative that could cut down on the overhead by using components that are far more stable. These components, called Majorana quasiparticles, are not real particles. Instead, they are special patterns of behavior that may arise inside certain physical systems and under certain conditions.