A team of physicists and engineers at the University of Colorado Boulder has discovered a new way to measure the orientation of magnetic fields using what may be the tiniest compasses around—atoms.

The group’s findings could one day lead to a host of new quantum sensors, from devices that map out the activity of the human brain to others that could help airplanes navigate the globe. The new study, published in the journal Optica, stems from a collaboration between physicist Cindy Regal and quantum engineer Svenja Knappe.

It reveals the versatility of atoms trapped as vapors, said Regal, professor of physics and fellow at JILA, a joint research institute between CU Boulder and the National Institute of Standards and Technology (NIST).