Silence, please: UNSW scientists create quietest semiconductor quantum bits on record

Researchers at UNSW Sydney have demonstrated the lowest noise level on record for a semiconductor quantum bit, or qubit. The research was published today in Advanced Materials.

For quantum computers to perform useful calculations, quantum information must be close to 100 per cent accurate. Charge noise – caused by imperfections in the material environment that hosts qubits – interferes with quantum information encoded on qubits, impacting the accuracy of the information.

“The level of charge noise in semiconductor qubits has been a critical obstacle to achieving the accuracy levels we need for large-scale error-corrected quantum computers,” says lead author Ludwik Kranz, a PhD student at UNSW’s Centre for Quantum Computation and Communication Technology (CQC2T) working with the Centre’s spin off company Silicon Quantum Computing (SQC).

“Our research has demonstrated that we can reduce charge noise to a significantly low level, minimising the impact it has on our qubits,” says Kranz.

“By optimising the fabrication process of the silicon chip, we achieved a noise level 10 times lower than previously recorded. This is the lowest recorded charge noise of any semiconductor qubit.”

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