Atomic precision qubits in a silicon crystal
15 Jan 2019 by qmcqmmjcbp.d qmcqmmjcbp.d
Quantum scientists in Australia have demonstrated the world’s first 3D atomic-scale quantum chip architecture.
UNSW researchers showed the feasibility of their 3D chip architecture unveiled in 2015. This uses single-atom quantum bits (qubit) aligned to control lines inside a 3D design, by extending the atomic qubit fabrication technique to multiple layers of a silicon crystal.
Leader of the study Professor Michelle Simmons said: “This 3D device architecture is a significant advancement for atomic qubits in silicon. To be able to constantly correct for errors in quantum calculations – an important milestone in our field – you have to be able to control many qubits in parallel.
“The only way to do this is to use a 3D architecture, so in 2015 we developed and patented a vertical crisscross architecture. However, there were still a series of challenges related to the fabrication of this multi-layered device. With this result we have now shown that engineering our approach in 3D is possible in the way we envisioned it a few years ago.”
The team, from the Centre of Excellence for Quantum Computation and Communication Technology (CQC2T), demonstrated how to build a second control plane – or layer – on top of the first layer of qubits, aligning the different layers in their 3D device within under 5 nanometers.
CQC2T researcher and co-author Dr Joris Keizer said: “We built the first plane, and then optimised a technique to grow the second layer without impacting the structures in the first layer.”
The researchers were able to measure qubit output of the device with a single accurate measurement rather than averaging out millions of experiments. Simmons said that the team is working towards large-scale architecture and eventual commercialisation of the technology – a quantum computer.
The research was published in Nature Nanotechnology.
