Delivering the 2017 Australia Day address on Tuesday, Professor Simmons said it was a "disaster" to try to make physics more appealing to girls by substituting rigorous mathematical problem-solving with qualitative responses.

"There is a big cost in this type of thinking," she said to an audience that included Premier Gladys Berejiklian.

"When we reduce the quality of education that anyone receives we reduce the expectations we have of them," she said.

A spokesman for the NSW Education Standards Authority (formerly BOSTES) said the new HSC science curriculum will commence in 2018.

He said: "The new courses address the exact concerns expressed by Professor Simmons.

"The physics and chemistry courses will have a greater focus on mathematical applications."

He also said there will be a reduction in the sociology-based content and an emphasis on practical investigations.

Professor Simmons' Australia Day speech focused on the need for Australians to attempt the difficult things in life.

"It is better to do the things that have the greatest reward; things that are hard, not easy," she said.

"If we want people to be the best they can be we must set the bar high and tell them we expect them to jump over it," she said.

"My strong belief is that we need to be teaching all students – girls and boys – to have high expectations of themselves."

Professor Simmons has certainly set the bar high for herself. She wants to realise her dream to build a working quantum computer, here, in Australia.

For her Cambridge was "too hierarchical and esoteric". The American culture, she said, restricts early-career researchers. When she arrived, people asked her "Why on Earth did you come?"

But for Professor Simmons the choice was easy.

"Australia offers a culture of academic freedom, openness to ideas and an amazing willingness to pursue ambitious goals," she said.

Professor Simmons is so proud of the one-way ticket to Australia she bought 18 years ago that she had it framed and sent to her brother for his 50th birthday.

From what she said was a "pretty rough" part of south-east London, she moved to Australia in 1999 after studying at Cambridge. Her big brother Gary went to the United States.

In her Australia Day Address on Tuesday, she said she often jokes with him that she got the better deal.

"Only I'm not joking," she told an audience, including NSW Governor David Hurley and Premier Berejiklian. "It's the truth. I genuinely believe it is better here."

Ms Berejiklian introduced Professor Simmons in what was her first official function as Premier.

Professor Simmons said: "On occasions like this, we tend to emphasise the beauty of our natural environment, our great lifestyle and the easygoing character of our people.

"This is a mistake ... it encourages us to shy away from difficult challenges. It will stop us from being as ambitious as we might be," she said.

Professor Simmons leads a storied team of dedicated scientists trying to do what many think impossible: build a new type of computer – a quantum computer – based on individual phosphorous atoms in silicon.

She said said: "Quantum physics is hard. Technology at the forefront of human endeavour is hard. But that's what makes it worthwhile."

Building a quantum computer is one of the greatest challenges of our time. Professor Simmons calls it the "space race of the computing era". There are three dedicated centres of excellence in Australia working on quantum technology, with a strong presence across Sydney's universities.

"Australia, for some reason, is disproportionately strong in quantum science. And, with billions of dollars of investment coming into this field from across the world, our challenge is to see if we can translate our international lead into high-technology industries," she said.

A working quantum computer would make currently impossible computing tasks possible. "Instead of performing calculations one after the other like a conventional computer, quantum computers work in parallel, looking at all possible outcomes at the same time," she said.

This would allow us "to solve problems in minutes that could otherwise take many thousands of years".

Australia, she said, is a great place to discover things. "I am grateful for that Australian spirit to give things a go and our enduring sense of possibility."

Professor Simmons said: "I want Australians above all to be known as people who do the hard things."

You can read the full transcript of Professor Simmons' speech at the Australia Day website. It will be broadcast on ABC Radio National on Thursday at noon.