Quantum computing engineers at UNSW Sydney have shown they can encode quantum information—the special data in a quantum computer—in four unique ways within a single atom, inside a silicon chip.

The feat could alleviate some of the challenges in operating tens of millions of quantum computing units in just a few square millimeters of a silicon quantum computer chip.

In a paper published in Nature Communications, the engineers describe how they used the 16 quantum ‘states’ of an antimony atom to encode quantum information.