Seeing the quantum future. literally
Sydney physicists have demonstrated it is possible to overcome the most significant hurdle to building reliable quantum technologies, in a major technical achievement.聽The research is published in Nature Communications.
We鈥檙e developing new capabilities that turn quantum systems from novelties into useful technologies
TEDxSydney
Trapped Ytterbium ions were used as one of the most advanced laboratory quantum systems for this study.聽 Professor Biercuk's research laboratories are now located in the , after six years as a visiting scientist at the National Measurement Institute.聽
Scientists at the University of Sydney have demonstrated the ability to 鈥渟ee鈥� the future of quantum systems, and used that knowledge to preempt their demise, in a major achievement that could help bring the strange and powerful world of quantum technology closer to reality.
The applications of quantum-enabled technologies are compelling and already demonstrating significant impacts 鈥� especially in the realm of sensing and metrology. 聽聽And the potential to build exceptionally powerful quantum computers using quantum bits, or qubits, is driving investment from the world鈥檚 largest companies.
However a significant obstacle to building reliable quantum technologies has been the randomisation of quantum systems by their environments, or decoherence, which effectively destroys the useful quantum character.
The physicists have taken a technical quantum leap in addressing this, using techniques from big data to predict how quantum systems will change and then preventing the system鈥檚 breakdown from occurring.
The research is published today in .
鈥淢uch the way the individual components in mobile phones will eventually fail, so too do quantum systems,鈥� said the paper鈥檚 senior author Professor .
鈥淏ut in quantum technology the lifetime is generally measured in fractions of a second, rather than years.鈥�
Professor Biercuk, from the University of Sydney鈥檚 and a chief investigator at the Australian Research Council鈥檚 Centre of Excellence for Engineered Quantum Systems, said his group had demonstrated it was possible to suppress decoherence in a preventive manner. The key was to develop a technique to predict how the system would disintegrate.
Professor Biercuk highlighted the challenges of making predictions in a quantum world: 鈥淗umans routinely employ predictive techniques in our daily experience; for instance, when we play tennis we predict where the ball will end up based on observations of the airborne ball,鈥� he said.
鈥淭his works because the rules that govern how the ball will move, like gravity, are regular and known.聽 But what if the rules changed randomly while the ball was on its way to you?聽 In that case it鈥檚 next to impossible to predict the future behavior of that ball.聽
鈥淎nd yet this situation is exactly what we had to deal with because the disintegration of quantum systems is random. Moreover, in the quantum realm observation erases quantumness, so our team needed to be able to guess how and when the system would randomly break.聽
鈥淲e effectively needed to swing at the randomly moving tennis ball while blindfolded.鈥�
The team turned to machine learning for help in keeping their quantum systems 鈥� qubits realised in trapped atoms 鈥� from breaking.
What might look like random behavior actually contained enough information for a computer program to guess how the system would change in the future. It could then predict the future without direct observation, which would otherwise erase the system鈥檚 useful characteristics.
The predictions were remarkably accurate, allowing the team to use their guesses preemptively to compensate for the anticipated changes.
Doing this in real time allowed the team to prevent the disintegration of the quantum character, extending the useful lifetime of the qubits.
鈥淲e know that building real quantum technologies will require major advances in our ability to control and stabilise qubits 鈥� to make them useful in applications,鈥� Professor Biercuk said.
Our techniques apply to any qubit, built in any technology, including the special superconducting circuits being used by major corporations.
鈥淲e鈥檙e excited to be developing new capabilities that turn quantum systems from novelties into useful technologies. The quantum future is looking better all the time,鈥� Professor Biercuk said.
