Centre Updates

Tests show integrated quantum chip operations possible

Quantum computers that are capable of solving complex problems, like drug design or machine learning, will require millions of quantum bits – or qubits – connected in an integrated way and designed to correct errors that inevitably occur in fragile quantum systems. Now, an Australian research team has experimentally realised a crucial combination of these capabilities on a silicon chip, bringing the dream of a universal quantum computer closer to reality.

They have demonstrated an integrated silicon qubit platform that combines both single-spin addressability – the ability to ‘write’ information on a single spin qubit without disturbing its neighbours – and a qubit ‘read-out’ process that will be vital for quantum error correction. Moreover, their new integrated design can be manufactured using well-established technology used in the existing computer industry.

The team is led by Scientia Professor Andrew Dzurak of UNSW Sydney, a program leader at the Centre of Excellence for Quantum Computation and Communication Technology (CQC2T) and Director of the NSW node of the Australian National Fabrication Facility.

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CQC2T Chief Investigator Professor Geoff Pryde elected Fellow of the Optical Society (OSA)

The Optical Society (OSA) Board of Directors has elected 98 members to the Society’s 2019 Fellows Class with the honour including CQC2T Chief Investigator Professor Geoff Pryde from Griffith University.

OSA Fellows are members who have served with distinction in the advancement of optics and photonics. No more than 10 percent of the total OSA membership may be Fellows at any given time, making each year’s honorees a highly selective group.

“I’m really honoured to be included amongst the Fellows of OSA, joining many wonderful researchers that I have admired through my career. It’s an inspiration to keep striving in challenging and exciting research directions.” Professor Geoff Pryde

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AI changing the way scientists carry out experiments

There's plenty of speculation about what artificial intelligence, or AI, will look like in the future, but researchers from The Australian National University (ANU) are already harnessing its power.

The group from the ANU Department of Quantum Science has been experimenting with trapping atoms at very cold temperatures, in their efforts to build a quantum communication network.

Now they've developed an artificial neural network with AI to help them run their experiments. Based loosely on the human brain, neural networks allow computers to "learn" to perform tasks.

"We use AI to control a large number of inputs to our experiment - the different laser and magnetic field settings - to seek out the best possible experimental conditions," said Dr Geoff Campbell, post-doctoral fellow at the Centre for Quantum Computation and Communication Technology.

"Because we have so many inputs we can only make educated guesses based on our understanding of what works best, but the AI is better at it than we are."
Cold atoms are an important part of new technology like precision sensors and atomic clocks.

This latest research has demonstrated the potential for AI to optimise cold atomic systems. The solution found by the AI can trap twice as many cold atoms in half the time.

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Prime Minister Prizes for Science Gala Dinner 17 October 2018

CQC2T Director Professor Michelle Simmons celebrates science excellence at the Prime Minister’s Prizes for Science gala dinner with Prime Minister Scott Morrison, Minister for Industry, Science and Technology Karen Andrews and Dean of Science at UNSW Dr Emma Johnston. The Prime Minister’s Prizes for Science are Australia’s most prestigious awards for outstanding achievements in scientific research, research-based innovation, and excellence in science teaching.

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New photonic chip promises more robust quantum computers

Scientists have developed a topological photonic chip to process quantum information, promising a more robust option for scalable quantum computers.

The research team, led by RMIT University’s Dr Alberto Peruzzo, has for the first time demonstrated that quantum information can be encoded, processed and transferred at a distance with topological circuits on the chip. The research is published in Science Advances.

The breakthrough could lead to the development of new materials, new generation computers and deeper understandings of fundamental science.

In collaboration with scientists from the Politecnico di Milano and ETH Zürich, the researchers used topological photonics – a rapidly growing field that aims to study the physics of topological phases of matter in a novel optical context – to fabricate a chip with a ‘beamsplitter’ creating a high precision photonic quantum gate.

“We anticipate that the new chip design will open the way to studying quantum effects in topological materials and to a new area of topologically robust quantum processing in integrated photonics technology,” says Peruzzo, Chief Investigator at the ARC Centre of Excellence for Quantum Computation and Communication Technology (CQC2T) and Director, Quantum Photonics Laboratory, RMIT.

“Topological photonics have the advantage of not requiring strong magnetic fields, and feature intrinsically high-coherence, room-temperature operation and easy manipulation” says Peruzzo.

“These are essential requirements for the scaling-up of quantum computers.”

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Making light work of quantum computing

Light may be the missing ingredient in making usable quantum silicon computer chips, according to an international study featuring #CQC2T Professor Timothy Ralph from the University of Queensland.

The team has engineered a silicon chip that can guide single particles of light – photons – along optical tracks, encoding and processing quantum-bits of information known as ‘qubits’.

The experiment, conducted primarily at the University of Bristol, proved that it is possible to fully control two qubits of information within a single integrated silicon chip.

A surprising result of the experiment is that the quantum computing machine has become a research tool in its own right.

“The device has now been used to implement several different quantum information experiments using almost 100,000 different reprogrammed settings,” Professor Ralph said.

“This is just the beginning; we’re just starting to see what kind of exponential change this might lead to.”

The research has been published in Nature Photonics. (DOI: 10.1038/s41566-018-0236-y)

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CQC2T physicist Dr Rose Ahlefeldt named ACT Scientist of the Year

Congratulation to CQC2T researcher Dr Rose Ahlefeldt from the Australian National University (ANU) who was named ACT Scientist of the Year.

Dr Ahlefeldt's research is trying to find the right materials to build the quantum memories needed for quantum computers. These computers could solve some of the world's "impossible" problems.

"I am trying to understand how the atoms in the crystals interact with the light, so I can choose the right materials to make better quantum memories." says Dr Ahlefeldt.

"One day we're going to build quantum computers that can solve problems that are impossible for our current computers. Researchers have already identified many uses for these computers, including enhancing artificial intelligence establishing secure communications and eventually building a quantum internet."

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Hundreds of school students get exclusive insights into the world of quantum

200 primary and secondary school students got a rare peek into what life as a scientist could be like, as Professor Michelle Simmons opened the doors of the Centre for Quantum Computation and Communication Technology (CQC2T) ahead of National Science Week.

When Scientia Professor Michelle Simmons became Australian of the Year 2018, her acceptance speech touched on themes that resonated with many school students and teachers: her encouragement of all young people to pursue what they love, to set their sights high, to tackle the hardest challenges in life and to be the creators – not just the users – of technology. Following the ceremony – and numerous subsequent speech invites from schools across Australia – Professor Simmons and her team decided to open the doors of the Centre for Quantum Computation and Communication Technology for one full day, to offer students the opportunity to see the team’s ground-breaking research in action – a first in the centre’s history.

Professor Simmons said the goal of the day was to open the students’ minds to the possibilities that a career in STEM offers. “When I was younger, I got to see a fabrication plant in the US, and observed how they make semi-conductor chips. It completely opened my mind to the world of possibility that was out there. I remember thinking that all children should see this. “So here we are in Australia, we've got this great facility of building chips in-house, so I'm hoping we opened the students’ eyes to what's out there, to all the kind of jobs they can have, and just get them excited by science.”

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.”

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Centre researchers set world record simulating quantum power

CQC2T scientists from the University of Melbourne have set a world record in simulating quantum power on a classical computer, a key step in becoming 'quantum-ready' ahead of when actual quantum computers are scaled up in size. Deputy Director of CQC2T, Professor Lloyd Hollenberg and team members Dr Charles Hill and lead author Masters student Aidan Dang, simulated the output of a 60-qubit quantum computer, which in general would require up to 18,000 petabytes, or more than a billion laptops, to describe – capabilities well beyond the largest supercomputer.


A representation of quantum computing in action showing the “forest” of differing probabilities that the machine uses to more efficiently guide it towards the answer to a problem. The above example is a simulation of a quantum computer finding the prime factors of a number using Shor’s Algorithm.
Picture: Matthew Davis, Gregory White and Aidan Dang

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