Physicists trap and suspend single positron of antimatter for months

Amazing stuff!

"... After capturing the fast-moving particle from radioactive decay, the scientists cooled it to nearly absolute zero. Then, they suspended the particle in a near-perfect vacuum, preventing it from touching ordinary matter—an encounter that would cause it to vanish.

By trapping and cooling a positron this way, the scientists created what they call a "one-positron quantum cyclotron." In this state, the positron essentially behaves much like an artificial atom with quantum energy levels scientists can precisely control and observe.

The advance ultimately could enable the most precise test yet of a fundamental symmetry between electrons and their antimatter counterparts. ...

team also demonstrated that they could precisely manipulate and detect the positron’s individual quantum energy states. By delivering carefully tuned microwaves, the team added tiny precise amounts of energy to the positron and detect its resulting quantum transitions. ..."

From the abstract:

"A one-positron quantum cyclotron is realized with a single positron suspended indefinitely in the magnetic field of a Penning trap.

This opens the possibility of quantum measurements of the positron magnetic moment at a precision much higher than attained with classical cyclotron motion. Comparing the magnetic moments measured using positron and electron quantum cyclotrons should provide the most stringent test of the fundamental 𝐶⁢𝑃⁢𝑇"

Physicists trap and tame single particle of antimatter for months

Scientists trap and tame a single particle of antimatter for months (original news release) "Trapped positron sets stage for Standard Model’s toughest test yet"

One-Positron Quantum Cyclotron (open access)

The tank in the center of the lab, lowered beneath ground level, holds the captured positron. 

Fig. 1 (a) Energy levels of a one-positron quantum cyclotron.
(b) Trap electrodes that confine the positron.

Fig. 2 The cryogenic dewars, superconducting solenoid, dilution refrigerator, and Penning trap.