Centre updates

Tuning into quantum: scientists unlock signal frequency control of precision atom qubits

CQC2T scientists, led by Prof Michelle Simmons, have achieved a new milestone in their approach to creating a quantum computer chip in silicon, demonstrating the ability to tune the control frequency of a qubit by engineering its atomic configuration.

The team from UNSW Sydney successfully implemented an atomic engineering strategy for individually addressing closely spaced spin qubits in silicon. The scientists created engineered phosphorus molecules with different separations between the atoms within the molecule allowing for families of qubits with different control frequencies. Each molecule could then be operated individually by selecting the frequency that controlled its electron spin.

“The ability to engineer the number of atoms within the qubits provides a way of selectively addressing one qubit from another, resulting in lower error rates even though they are so closely spaced,” says Professor Simmons. “These results highlight the ongoing advantages of atomic qubits in silicon.”

Tuning in and individually controlling qubits within a 2 qubit system is a precursor to demonstrating the entangled states that are necessary for a quantum computer to function and carry out complex calculations.

“We can tune into this or that molecule – a bit like tuning in to different radio stations,” says Sam Hile, lead co-author of the paper and Research Fellow at UNSW. “It creates a built-in address which will provide significant benefits for building a silicon quantum computer.”

Read paper here
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CQC2T partner explains motivation for quantum computing investment

Telstra's Chief Scientist Professor Hugh Bradlow explains the telco giant's commitment to becoming a world class technology company in this piece for Exchange. The company's long-term approach has seen it invest in Australia's first quantum computing company, Silicon Quantum Computing Pty Ltd.

Guests tour UNSW's quantum computing laboratories at the launch of Silicon Quantum Computing Pty Ltd

The company is a first-of-its-kind collaboration between UNSW, the Commonwealth and NSW governments, Commonwealth Bank Australia and Telstra. CQC2T Director Prof Michelle Simmons is a founding member of the company board.

Read more at the Telstra Exchange

CQC2T researchers are connecting up the global quantum internet

A team of researchers led by A. Prof Matthew Sellars at The Australian National University have shown that an erbium-doped crystal is a practical building block for a global quantum internet.

Dr Rose Ahlefeldt and A. Prof Matthew Sellars operating a high resolution dye laser (used to study rare earth crystals) in the solid state spectroscopy laboratory at ANU. Image credit: Stuart Hay, ANU

The material is uniquely suited to enable a global quantum telecommunications network, achieving coherence times of more than a second and operating in the same 1550nm band as existing fibre optic networks.

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Access the full paper at Nature Physics.

Watch a video about the result.