The Best Australian Science Writing 2014 (38 page)

The computer they are trying to build may be constructed using silicon chips not dissimilar from those in a conventional computer. But the quantum computer will process information in an utterly different way.

In normal so-called digital computers, the basic units of information, called bits, are built from tiny transistors that can exist in two states, either a 0 or a 1, depending on whether current is passing through them.

But at the quantum scale, cut and dried notions such as 0 or 1 no longer apply. Down at the level of the fundamental particles that make up matter, objects become more like the ‘shapeshifters' of science fiction, existing in a combination of all their different possible states at the same time. Scientists refer to this phenomenon as ‘superposition'. And for decades, they have theorised about the possibilities. If they could build computers from these shapeshifter quantum systems, then each ‘quantum bit' – or ‘qubit' – of information, could, in essence, be both a 0 and a 1 simultaneously. When you combine this with the phenomenon of ‘entanglement' that Morello demonstrated via the bits of paper to his audience that night in Sydney, the arithmetic of computing is transformed.

There are really no shortcuts to understanding quantum computing, Morello admits. But in essence its power comes down to the mind-boggling amount of information that quantum bits contain because of superposition. For example, with three standard computing bits, it is possible to specify eight different numbers. 000, 001, 010, 011, 100, 101, 110 and 111 represent the numbers 0, 1, 2, 3, 4, 5, 6 and 7 respectively.

With three qubits, there are also the same eight ‘basic states' you could write with three classical bits. But because the qubits are shapeshifters, all eight numbers are also present
at the same time
. By the time you get to 300 qubits, you have a vast computational capacity. ‘To describe the quantum state of 300 fully entangled qubits you need an amount of classical information equivalent to 2
³⁰⁰
, which is as many atoms as there are in the universe.'

Good luck understanding the details. But what is relatively easy to grasp is that the crunching power promised by a quantum computer is a leap ahead of that offered by a classical computer.

There's a lot of promise. But constructing useful qubits in the real world is a major headache. Among the many challenges
is the fact that quantum particles tend to be very susceptible to interference: if they interact with their environment, the quantum state is destroyed.

Yet over the past ten years or so, researchers around the world have managed to build qubits in a multitude of ways. Some have suspended ions in vacuums, others have used photons of light or impurities in diamond crystals and others, like the D-Wave, have used switching currents in a superconductor.

Morello, Dzurak and their colleagues create their qubits by embedding phosphorus atoms into the crystal structure of silicon. They have shown that they can detect the magnetic orientation (or ‘spin') of the phosphorus atom and of a single electron orbiting the atom's nucleus. It's this characteristic, the spin, that serves as the qubit.

Morello's lab at UNSW makes for a stark scene change from the steamy tropic-themed Surry Hills bar. With high ceilings, large windows, and clusters of high-powered machinery around the place, it's a light, spacious no-nonsense room. Morello and a couple of his students are going to show me how the qubit works. First, they chill the silicon and its single phosphorus atom to nearly absolute zero. This is vital because at higher temperatures, the spin of the particle will change spontaneously.

By pulsing microwave radiation along electrodes in a tiny circuit laid down on the chip, they can change the spin. When its spin is measured as being ‘up', an electrical current can flow along the circuit and when it is ‘down', the current stops flowing. On a computer screen, the output of this is displayed as a sine wave oscillating up and down as the microwaves push the spin from up to down and back again. The top of the wave represents a qubit readout of ‘1', while the bottom of the wave is ‘0'.

The fact that the system is also reading intermediate points along the graph between zero and one shows the phenomenon of superposition in action, says Morello. Each measurement is
either zero or one but it is possible to represent the quantum shapeshifters by repeating each measurement hundreds of times and counting the frequency with which a 0 or a 1 is measured.

In many ways, the team is running behind its competitors. For instance, researchers using other approaches to making qubits, such as charged atomic particles confined in electromagnetic fields or the D-Wave, have already managed to entangle the behaviours of numerous qubits. By contrast Morello and colleagues have only managed to produce a single qubit. But Morello says their hardware offers better prospects for scaling up to larger machines containing more qubits because silicon can be purified of its magnetic contaminants, eliminating any magnetic noise that destroys the delicate quantum states of the spin qubits.

Morello's game is to perfect the building block, then race ahead to large-scale automated production. ‘The silicon route to the quantum computer has several advantages. It offers the best protection of quantum states of any solid-state system, and the fabrication technology we use is the same as what's used to make normal, existing computers. The industrial infrastructure to build the devices is already there; we don't need to create a new industry,' Morello says.

Within the next few years, their plan is to build a small-scale quantum computer made up of ten qubits that would demonstrate all the basic components necessary for a bigger quantum computer. ‘We could start testing the performance of each part and how they behave when we put them all together. From the point of view of computational capacity, they might also start to be useful to simulate some simple molecules, or the behaviour of materials in which the electrons interact in a complicated way.'

* * * * *

On the personal front, things have also gone well for Morello since moving to Sydney. Not long after he arrived in the city in 2006, he was dancing at a gay nightclub on Sydney's Oxford Street when he met the jazz pianist and writer, Carolyn Shine.

‘When I said I was a quantum physicist her eyes lit up and she was like “seriously, let's stay in touch,” she was totally fascinated.' Shine and Morello became friends, and she introduced him to the Sydney music scene, where he has come to feel at home. (Shine passed away from cancer in 2012.)

These days, when he isn't in the lab or wrestling equations at home he's just as likely to be at a nightclub, supporting his girlfriend Lindsay Rose (also known as Rita Fontaine or Johnny Castrati), a well-regarded cabaret and burlesque performer.

Morello says the communities of burlesque performers, jazz musicians and scientists share many attributes. Partly that's because the arts and sciences are both intrinsically creative. But mostly it's to do with the importance of curiosity, and of giving yourself totally to your passion.

‘It's about connections and interactions,' he says. ‘These are all special communities of people who are curious, outgoing and creative, with the courage to express “the real you” and to follow through.'

Pitch fever

Life, the universe and Boolardy

Here be dragons

Vanessa Hill

In early January 2014, the CSIRO received a letter from Sophie, a seven-year-old girl. All she wanted was a dragon.

Hello Lovely Scientist [she wrote], My name is Sophie and I am 7 years old. My dad told me about the scientists at the CSIRO. Would it be possible if you can make a dragon for me? I would like it if you could but if you can't thats fine. I would call it Toothless if it was a girl and if it is a boy I would name it Stuart. I would keep it in my special green grass area where there are lots of space. I would feed it raw fish and I would put a collar on it. If it got hurt I would bandage it if it hurt himself. I would play with it every weekend when there is no school. Love from Sophie.

‘Our work has never ventured into dragons of the mythical, fire-breathing variety. And for this, Australia, we are sorry,' we replied.

Sophie's letter, and our response, made an unexpected splash across the globe. It was featured on
Time,
the
Huffington Post
, the
Independent
, Yahoo
–
the list goes on. People contacted us offering to help; financial institutions tweeted their support, and
DreamWorks Studios phoned (seriously), saying they knew how to train dragons and wanted to speak with Sophie.

The dreams of one little girl went viral.

We couldn't sit here and do nothing. After all, we'd promised Sophie we would look into it.

So on 10 January 2014, at 9.32 a.m. (AEDT), a dragon was born – Toothless, a blue female dragon. Her species?
Seadragonus giganticus maximus
.

Generated in titanium via 3D-printing, Toothless came into the world at Lab 22, our additive manufacturing facility in Melbourne. The scientists there have printed some extraordinary things in the past – huge anatomically correct insects, biomedical implants and aerospace parts. So they thought a dragon was achievable.

‘Being that electron beams were used to 3D-print her, we are certainly glad she didn't come out breathing them … instead of fire,' said Chad Henry, our additive manufacturing operations manager. ‘Titanium is super strong and lightweight, so Toothless will be a very capable flyer.'

Sophie's mother said Sophie was overjoyed with our response and has been telling everyone dragon breath can be a new fuel. ‘All her friends are now saying they want to be [scientists] and Sophie says she now wants to work at CSIRO. She's saying Australian scientists can do anything,' she told the
Canberra Times
.

We'd love to have you in our team, Sophie. For now, stay curious.

Uniquely human

The quantum spinmeister

Advisory panel

Professor Merlin Crossley is Dean of Science at the University of New South Wales. He studied at the Universities of Melbourne and Oxford (as a Rhodes Scholar) and has carried out research on genetic diseases at Oxford, Harvard, Sydney and UNSW. He serves on the Trust of the Australian Museum, the Boards of the Sydney Institute of Marine Science, the Australian Science Media Centre, and New South Innovations. He is an enthusiastic science communicator.

Professor Suzanne Miller, CEO and Director of the Queensland Museum Network, is a geologist with particular interest in promoting engagement with science and culture through collections and museum participation. An affiliate professor at the University of Adelaide, she has held previous roles at the South Australian Museum, National Museums Scotland, British Antarctic Survey, various universities and the BBC. She has authored more than 50 scholarly papers and articles and presented more than 100 invited addresses on Earth and planetary sciences and lifelong learning.

Professor Fred Watson has been astronomer-in-charge of the Australian Astronomical Observatory since 1995, but is best known for his radio and TV broadcasts, books and other outreach programs including science tourism. Fred is a musician, too, with both a science-themed CD and an award-winning libretto to his
name. He was made a Member of the Order of Australia in 2010. Fred has an asteroid named after him (5691 Fredwatson), but says that if it hits Earth, it won't be his fault.

Acknowledgments

Ian Lowe's foreword grew from his keynote address to the 2014 Australian Science Communicators Conference. A shorter version was published on
The Conversation
on 3 February 2014.

Ludwig Leichhardt's Australian journals spanning 1842–1844 are held in the Mitchell Library, Sydney. They were translated and edited by Thomas A Darragh and Roderick A Fensham and published for the first time as part of the
Memoirs of the Queensland Museum
in 2013.