The quantum spinmeister
Physicist Andrea Morello is harnessing the 'spin' of quantum particles to create a potentially groundbreaking new way of computing. But you can forget the stereotypes. This man's a demon in the lab and on the dance floor, Stephen Pincock discovers.
It’s 10 o’clock on a steamy summer’s night when Andrea Morello hits the stage of a small bar in the hip Sydney district of Surry Hills. There’s a tropical sunset painted on the wall and plastic vines draped over the bar. So many people have crammed into this over-stuffed room that there is barely space to stand, let alone sit. If there’s a fire, we’re in trouble.
The crowd is here for a monthly event called “Nerd Nite”, where scientists talk about their research to a young and enthusiastic audience. (As the website says, “It’s like the Discovery Channel – with beer”).
Tonight the mob has already cheered talks about the Higgs Boson and the molecular anatomy of bacterial flagella from a couple of sharp and funny young science guns. Now the compere introduces Morello, an associate professor in quantum nanosystems at the ARC Centre of Excellence for Quantum Computation and Communication Technology, based at the University of New South Wales.
Six-foot-something and greyhound thin, Morello, aged 41, wears his long wiry hair pulled back into a luxuriant ponytail. There’s a soul patch under his lower lip and a dangerous twinkle in his eye. And you can forget about the usual young-scientist’s uniform of faded T-shirt and jeans. This researcher is dressed for impact in a pair of skin-tight burgundy pants, pointy black shoes and a snowy white shirt with origami pleats and a kind of vampire collar.
Over the past couple of years, Morello and his colleagues have emerged as frontrunners in a scientific race to build a computer that harnesses quantum physics, the laws that govern the physical world at the smallest scale.
Their hope and expectation is that such a machine will one day solve problems beyond the capacity of regular computers. With their extraordinary characteristics, quantum computers promise a step change when it comes to solving computing problems, especially those to do with “optimisation”. The classic example is that of the travelling salesman. With dozens of stores on his beat, what route will deliver the best efficiency in terms of time and distance travelled? Optimisation problems like this crop up in applications as varied as stock market trading, medical treatments, scheduling airlines, and designing drugs. A classical computer has to crunch through each option sequentially to find the answer. A quantum computer promises to do it simultaneously. In hope of paving the way to a quantum computing world, Google and NASA have teamed up to buy a D-Wave quantum computer. While chemists at Harvard University hope the same computer will help them find the most energetically stable way to fold a protein chain, an aid to designing new drugs.
But companies such as D-Wave have got where they are on the back of experimental technology that has raised many a cynical eyebrow. By contrast Morello and his colleagues Andrew Dzurak and Michelle Simmons, have captured the international limelight by providing a proof of concept that such a machine could be built using the material that forms the basis for every computer you’ve ever owned – the good old silicon chip.
For his “intellectual leadership in developing the silicon components to make quantum computing possible”, Morello was awarded the prestigious 2013 Malcolm McIntosh Prize for Physical Scientist of the Year, awarded by the Prime Minister at a black tie event in Canberra last October.
For anyone who gives credence to the tired stereotype of scientists and engineers as unimaginative plodders and pocket protector-wearing, unworldly, antisocial geeks, Morello offers a startling corrective. Uncompromising, charming, and intellectually rigorous, he’s a demon in the lab and on the dance floor.
He wants to convince his audience that quantum physics is not as mysterious as people describe it. 'Every time I go to a cocktail bar, this is the conversation I have.'
He’s also a willing and entertaining science communicator, with a facility for charming explanations of the quantum world. Tonight, he wants to convince his audience that quantum physics is not as mysterious as people describe it. “Every time I go to a cocktail bar, this is the conversation I have,” he says with a knowing smile. “So this talk is just my usual pickup line, which I’m going to regurgitate for you.”
For the following 15 minutes or so, he’s got the overheated audience in the palm of his hand. As he talks, he gestures in front of him, as if massaging the concepts of quantum physics out of the thick summer air. And indeed Morello in full flight has the ability to make you believe you're starting to comprehend the complexities of the quantum world, if only for a moment.
He calls two volunteers up to help him with a demonstration of the mysterious phenomenon of “entanglement”. It’s the word quantum physicists use to describe the fact that the characteristics of two quantum particles can become inextricably linked, so that if you measure a property of one, the other will instantly be found to have a value that correlates, no matter how far apart they are.
He flirts and cajoles as he hands “Bruce” a piece of paper and two pens, one red, one blue. He also hands “Angela” a coin and asks her to flip it.
If it’s heads, Bruce’s job is to take the blue pen and write +1 on the left and -1 on the right of the paper, or the reverse if it’s tails. Angela repeats the coin-toss. Bruce is told to turn the paper over and follow the same instruction, this time writing the numbers using the red pen. Lastly he is told to cut the paper in half. Bruce keeps one side; Angela takes the other. They each have a piece of paper with either +1 or -1 written in blue on one side and +1 or -1 written in red on the other. They seal their pieces of paper in envelopes and send them out into the crowd. When a guy in the audience opens the first one, he calls out that it's a +1 written in blue. This means, of course, that the other envelope must contain a piece of paper with a -1 in blue on it.
Albert Einstein famously dismissed quantum entanglement as
'spooky action at a distance'.
"We say that the cards are 'classically' correlated," explains Morello. "Angela and Bruce could go to their homes and at midnight Bruce could check his paper and instantly know what blue number Angela has on her paper." Nothing surprising here, he says, as Bruce already knew that the correlation was there.
But in the quantum world, this isn't the case, he explains. In entangled quantum systems the numbers are not “pre-written” on the paper, only “appearing” when you perform a quantum measurement. And the outcome of the measurement depends on which side of the paper you decided to look at.
In other words, if the pieces of paper were quantum-mechanically entangled, when Angela and Bruce go home, the numbers that appear on Angela’s paper would actually depend on which side of his paper Bruce decided to read.
And so the audience gets an inkling of the weirdness of quantum entanglement.
Albert Einstein famously dismissed it as “spooky action at a distance”, but Morello tells us that scores of experiments have shown that this really is the way quantum particles work.
In fact, entanglement is the basis for the very chemical bonds that hold the molecules of our own bodies together, he says before reaching for a sip of beer.
“It’s just the way the world works, so suck it up, OK? If you think this stuff is weird, then you’re weird.”
The day before his Nerd Nite performance, Morello pulled up Google Maps on his office computer to show me the village in Northern Italy where he grew up, a tiny place of 3,000 souls called Cumiana, right at the foot of the Alps.
As he virtually navigated through the streets of the town he gave me a potted history: the only son of a factory worker and a schoolteacher, he was a child who enjoyed school, excelling in Italian grammar and literature, music and history. “It sounds arrogant to say, but I effortlessly got top marks in everything.”
Science wasn’t a big part of life until high school, and even then his practical-minded parents guided him towards electrical engineering, a discipline where he could get a job straight after graduation.
'Nietzsche opened my eyes to all sorts of petty excuses that people make for themselves to be mediocre.'
Meanwhile his intellectual horizons expanded, as he developed a passion for avant garde jazz and Nietzsche. “That had a very big impact on me. It made me in a sense quite cruel and unforgiving. Nietzsche opened my eyes to all sorts of petty excuses that people make for themselves to be mediocre. Nietzsche helped me make a point of stepping beyond that. I was a very cocky teenager back in those days. Very, very cocky.”
He landed a place in the prestigious electrical engineering department at the Polytechnic University of Torino, where standards were high and the student attrition rate brutal. Of the 900 students who enrolled in his year, only 100 graduated five years later. He survived, and was drawn to physics courses that introduced him to the fundamentals of the physical world – quantum mechanics, solid state physics, superconductivity.
“I did all that and I reeeallly liked it,” he says, the word stretched out emphatically.
After hours, Morello was finding he also liked what you might call an alternative lifestyle. He started visiting jazz clubs in town and hanging out with squatters who had taken over the city’s abandoned public buildings. “There was always something going on, there were concerts and movie nights and all sorts of activities taking place.”
A teacher at the university, Renato Gonnelli, had a contact at a famed magnetic field laboratory in Grenoble, France, where Morello went to complete his final year thesis. In a reference letter he wrote some years later, Gonnelli praised his former student’s “great experimental ability” and his “uncommon facility in quickly learning new topics”.
For the young lad from a small country town, the Grenoble lab was an inspiring place, with Nobel laureates dropping by to use the world-class facilities. And from there he made further connections that led him to the Kamerlingh Onnes Laboratory, a leading ultra-low-temperature lab at the University of Leiden, The Netherlands, where he worked with Jos de Jongh, a formal, rigorous professor of magnetism with impeccable status in his field. “He’s the one who insisted that I go to the very roots of any problem I was interested in.”
Next, Morello moved to the University of British Columbia at the invitation of the eminent theorist Philip Stamp, where he developed a theory of the quantum dynamics of electron spin. “That’s where I got to the deepest realms of quantum mechanics. He fed and nurtured my interest in the foundations of quantum physics.” Like Gonnelli, Stamp was impressed by Morello’s passion for learning, and his creativity, self-confidence and ambition. “It's hard to say whether he plays harder or works harder, but he does both pretty hard,” Stamp told me.
Down at the level of the fundamental particles that make up matter, objects become more like the 'shapeshifters' of science fiction.
These larger than life figures were giving Morello an idea of what it takes to be a productive scientist. “What they taught me was to persevere in the research you believe is important and interesting and be very thorough at it,” says Morello. “If I look at the spectrum of scientists I’ve interacted with, the ones who have left the biggest imprint on the way I do science now are the ones who will take one problem and just get to the bottom of it.”
In 2006, Morello took the biggest gamble of his career, deciding to join the team at the University of New South Wales at the invitation of Professor Andrew Dzurak, to try and build the components of a quantum computer.
“When I came here, it was a very courageous decision,” he says. “There was a perception that this was a project that was interesting, exciting, challenging, but it might be on the far side of what can be done.”
So far, things could hardly have gone more swimmingly. Dzurak says Morello’s ability to combine hands-on experimental physics with an extremely good grasp of theory has been crucial to their success. “He’s a very rigorous physicist both theoretically and experimentally.” Clearly they make for a formidable team. Since 2010, there have been three publications in Nature. And in 2011 they were awarded the prestigious Australian Eureka Prize for Scientific Research.
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 be, in essence, both a 0 and 1 simultaneously.
In essence quantum computing power comes down to the mind-boggling amount of information that quantum bits contain.
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, 111, represent the numbers: 0, 1, 2, 3, 4, 5, 6, 7.
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.
Physicists like Morello are able to translate this shifty information. Alas for the uninitiated, it is not so easy.
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 2300 bits, which is as many atoms as there are in the universe.”
Good luck with 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 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 10 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 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, spin, that serves as the qubit.
Morello’s lab at the University of NSW 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 “one”, while the bottom of the wave is “zero”.
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 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 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 10 qubits that would demonstrate all the basic components necessary for any 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, who passed away from cancer in 2012, introduced Morello to the Sydney music scene, where he has come to feel at home.
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.”
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