Looks like an [atomic spin](...
User TenPoundSledge, in the For the identification of mysterious objects subreddit,
Looks like an [atomic spin]( https://physics.aps.org/synopsis-for/10.1103/PhysRevLett.115.206803) symbol to me.
Looks like an [atomic spin]( https://physics.aps.org/synopsis-for/10.1103/PhysRevLett.115.206803) symbol to me.