Entangling Atoms to Measure Magnetic Fields

By applying the quantum property of entanglement (where two particles behave exactly the same, even while separated) two individually trapped single atoms can be used to measure magnetic fields. This science supports mineral prospecting, submarine exploration and defence among other applications. The work is a collaboration with Singaporean researchers and is being led by University of Otago Associate Professor. Mikkel F. Andersen. He says entanglement enhancement can be hard to implement in practice, since it is often fragile, and short lived when moving atoms heat up. But a process called “spinchanging collisions” can entangle the magnetic substates of two atoms even when they’re warm, making the approach easier to use. The team has shown that such entanglement can be used to enhance the measurement of magnetic fields, yet it is unclear if it can be used to measure the rate of change of such fields. One of the desired outcomes is development of an experimental protocol for separating the two atoms. Knowing how to separate atoms after they’ve interacted (though a process known as “tweezing”) could be widely applied in technologies such as quantum computers.