He grew up surfing along the southern Queensland coastline but now Dr Jay Gambetta is riding a different kind of wave.
The Griffith University alumnus is one of the world’s leading minds in quantum computing, a branch of quantum theory that promises to fundamentally change the way we solve humanity’s most pressing problems.
As Manager, Theory of Quantum Computing and Information, at international technology giant IBM, Dr Gambetta helps spearhead the company’s drive to build a universal quantum computer. Capable of solving complex equations that classical computers are unable to, a universal quantum computer would revolutionise research in any number of fields.
“Think of quantum computing as a new model of computation, one that doesn’t obey the same laws as every other computer out there,” Dr Gambetta, 39, says.
“Those computers are bound by the laws of physics in what they can do. Quantum obeys a new set of laws and those laws allow for something called quantum randomness – where something can be in a definite state but still behave randomly.”
Classical computers run on bits: single pieces of information that only exist in two states – 0 or 1. Whereas quantum computers use quantum bits, or ‘qubits’, which can represent the 0 state, the 1 state, or a combination of both, known as superposition.
“Then there is the concept of entanglement, where particles individually look random but, when you look at the whole, they have correlations,” Dr Gambetta says. “So there’s more information in the whole than there is in the parts. Putting things together gives you access to far more information than you would understand in classic computing.
“And that means problems that are hard for a traditional computer can become easy for a quantum computer. It gives us a chance to probe nature in a way we’ve never probed it before.”
Raised in Redcliffe, north of Brisbane, Dr Gambetta spent summers probing nature his own way, surfing up and down Queensland and NSW.
“I wouldn’t say I planned to be a scientist from a young age,” he says. “I had planned to do something with my hands, either working with wood or on cars. But as I got more into education I found I really loved science.”
“I had a postgraduate scholarship that you could use at basically any Australian university, but I really wanted to work with [Griffith’s] Howard [Wiseman].”
Dr Gambetta studied a Bachelor of Science (Physics) with Honours at Griffith, graduating in 1999.
“When I was looking for a university to go to, Griffith offered a science degree that focused on learning about lasers and I thought, ‘This sounds cool’,” he says.
“Over time, I realised I had more of an interest in the physics side rather than the mathematics side, so focused more on that.”
Like most who encounter quantum theory, Dr Gambetta was intrigued.
“The courses I always end up doing are the ones I least understand, and quantum is one of the hardest to grasp so I wanted to learn more about it.”
Griffith has a track record of introducing curious minds to the quantum world. Since the university’s foundation in 1975, researchers have explored quantum dynamics and tackled difficult conceptual problems in quantum physics.
“One of the main reasons I stayed and did my PhD at Griffith (on theoretical quantum physics) was because of Howard Wiseman,” Dr Gambetta says.
“He taught courses that really struck an interest in me. I had a postgraduate scholarship that you could use at basically any Australian university, but I really wanted to work with Howard because he is a great teacher.”
Following the quantum path led Dr Gambetta from Griffith to a postdoctoral position at Yale University, then research roles at University of Waterloo’s Institute of Quantum Computing, in Canada. He joined IBM, where he is based in New York, in January 2011.
As the principal theoretical scientist behind IBM’s quantum computing effort, Dr Gambetta led the IBM Q Experience, a project enabling public exploration of quantum computing.
“In 2016, we put the first cloud-based quantum computer online; it allows anyone to come and use a quantum computer,” he says.
“It changed the perception of quantum computing because you didn’t have to be in a lab – anyone could use it.
“Now we’re working on open source software called QISKit (Quantum Information Software Kit) that allows anyone to build, compile, execute, and contribute applications on a quantum computer.
“This community is growing fast – there are more than 85,000 users. I would love to see students all over the world adding their ideas.”
Another challenge is working out how to effectively harness the immense potential quantum computing offers.
“I still do a lot of research because it’s fundamentally still a new theory and we’re working every aspect out of it,” Dr Gambetta says.
“A big question I work on is how do you turn this resource into what we like to call a ‘quantum advantage’? Discovering this advantage and learning how to use this advantage in real-life applications is a big part of my day-to-day work.”
In April, Dr Gambetta was named an IBM ‘fellow’ in recognition of his work with the 107-year-old company. IBM appoints a select number of fellows each year from a staff of more than 360,000.
His path might have been very different, with the lure of the waves briefly threatening to wipe out his then-fledgling quantum career.
“After my PhD, the first thing I did was go and shape surfboards at Broadbeach with some of my friends for about six months. Then Howard convinced me to come back and do some research with him,” Dr Gambetta says.
While his love of surfing hasn’t passed down to his two children in the chillier climate of the United States’ east coast (“we like to go snowboarding in winter”), his love of science has.
“I have shown them how to use the IBM Q Experience and they like to muck around on it.”
Despite its steep learning curve, the quantum world offers plenty of opportunity for young scientists.
“It’s a great career choice for people to get into quantum at the moment,” Dr Gambetta says.
“This is definitely emerging as a new technology and it’s still in its early days; there’s still lots to be done. If you like math and you like tinkering, I definitely would encourage people to do it.”
In the unpredictable field of quantum computing, even the experts are still learning.
“Getting your head around the math allows you to think about nature in a different way,” Dr Gambetta says.
“Because there’s so much we still don’t know about the potential of quantum computing, it never gets boring. There’s always new things to discover.”