September 26, 2022

Quieter semiconductor quantum bits

Researchers at UNSW Sydney have demonstrated the lowest noise level on record for a semiconductor qubit.

In any semiconductor platform such as silicon, charge noise is caused by imperfections in the material environment that hosts qubits. This noise interferes with quantum information encoded on qubits, impacting the accuracy of the information.

By reducing the impurities in the silicon chip and positioning the atoms away from the surface and interfaces where most of the noise originates, the team were able to produce the record-breaking result, a noise level 10 times lower than previously recorded.

The next challenge will be to move to isotopically pure crystalline Si-28 to capitalise on the long coherence times already demonstrated by the team. It would be possible to achieve a 99.99% fidelity in atom qubits in silicon. (

The research was published in Advanced Materials.

Read more.