Mingyu Sun, an SQA PhD Scholar from China exploring new approaches to error mitigation at UTS [SQA/Grant Turner]

MINGYU SUN BEGAN her research career in China as an experimentalist in nanotechnology, pivoted to exploring machine learning for quantum computation, and later signal processing while in the U.S. – and is now wrangling with quantum theory in Australia. And she loves it.

“I experienced three different research areas, three totally unrelated fields,” Sun said. “Now my research focus is error correction in quantum computation, and this is my favourite. There are diverse directions you can take, there are a lot of things to be explored.”

Brought up in Wuhan and a physics graduate from the China University of Geosciences, she went on to study nanotechnology at the University of Georgia. But after being exposed to quantum mechanics in coursework, she changed fields to machine learning to help address the errors that often arise in quantum computing.

Later she was lured to the University of Maryland Baltimore County by a professor working in signal processing of medical data, who offered her a fellowship. “She was a very strong, influential professor, and really inspiring,” recalled Sun. After a few fruitful years, Sun felt drawn back to quantum computing.

Lured by the beauty of quantum theory

That’s when Sun discovered the SQA PhD Scholarship, and the opportunity to work with A/Prof Chris Ferrie at the Centre for Quantum Software and Information at UTS. “They were looking for students to work in large scale quantum tomography, and I had recently read a very interesting paper in the field. So, I was quite excited [by the opportunity].”

SQA PhD Scholar Mingyu Sun is working on new theoretical techniques at UTS under A/Prof Christopher Ferrie

She’s now buried in equations, wrestling with the destructive nature of measuring things at the quantum scale – as soon as you do, the quantum state collapses. Quantum tomography offers a possible path to multiple non-collapsing measurements that could help with error correction in quantum computers, which – because of their fuzzy property – are prone to spitting out errors.

“There’s a good chance I could see this implemented in a laboratory setting or in a real device,” she said. And her time at UTS has given her an insight: a quantum PhD also opens doors in industry: “Previously I would have preferred research at a university, but now I see start-up companies are also doing fantastic work.”

Apart from the excitement of the field, Sun has really relished the sense of community among SQA students across the four universities – UTS, UNSW, Macquarie and the University of Sydney – who take part in joint seminars, events and organise their own social functions.

“Particularly for international students, it’s very important to have a sense of belonging. SQA really tries to foster that, where students get to know each other and what other people are working on. It’s quite an enjoyable thing.”

Almost mystical

Riddhi Ghosh has had a similar experience. “I’m grateful that I’m part of SQA. For a while, I had a really hard time in my PhD with projects not working out. Then I realised from other students that these things happen to them too.

“SQA has something that most places are lacking – this peer network. This was very helpful when I moved to Australia. Most of the friends I had for the first year were from SQA,” Ghosh said.

She has always been fascinated by physics – she loves the fact it’s littered with baffling behaviours that are almost mystical. 

Riddhi Ghosh, an SQA PhD Scholar from India is studying at Macquarie University under A/Prof Alexei Gilchrist

Hypnotised by quantum mechanics

“I read Stephen Hawking’s A Brief History of Time in eighth grade, and I did not understand a word of it,” she recalls. “It was always like my motivation to know enough physics so that I could understand that book. Over time, there were more and more books. But there were always more mysteries. Plus, I had really good teachers who encouraged me.”

Originally from Asansol in eastern India, Ghosh pursued a bachelor’s in physics at the University of Calcutta, then a master’s at the Indian Institute of Technology in New Delhi. She was almost hypnotised by quantum mechanics. “It’s so nice. There is so much we don’t know. And it would be great to try to actually figure out how things work. I realised that I just loved it.”

Planning to take on a PhD, she had been exploring programs in Singapore and Europe, when a supervisor recommended that she look at work being done at the Macquarie Centre for Quantum Engineering at Macquarie University. They were looking for a PhD student to explore the intricate connections between the two dynamic fields: quantum control and thermodynamics. She was sold.

Between theory and experiment

Now working under A/Prof Alexei Gilchrist and Prof Daniel Burgarth, she is trying to construct a theoretical framework that incorporates the principles of quantum thermodynamics for the efficient and optimised control and manipulation of a quantum system.

“It’s kind of between theory and experimental,” she said. “I also work in collaboration with Prof Thomas Volz group [at the ARC Centre of Excellence for Engineered Quantum Systems]. I have a foot in both worlds.”

It’s also broadened her horizons, she said. “I had always thought that once you start a PhD, the only way forward is in academia. That’s completely changed – I see PhD students joining companies and still doing quantum. It’s an option for me now, and one I would never have considered.”

Find out more about our PhD scholarship programs. Or search through the more than 100 SQA scientists and engineers working on quantum technologies in Sydney who are available to supervise PhD students.

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