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What next for quantum computers?
Social science
Analysis Computing
Half of your career success may be down to luck
What next for quantum computers? Google appears to have reached “quantum supremacy”, but there is still a long way to go before the technology is useful, reports Chelsea Whyte
Donna Lu
QUANTUM computing is now ready to go – or is it? Google appears to have reached an impressive milestone known as quantum supremacy, where a quantum computer is able to perform a calculation that is practically impossible for a classical one. But there are plenty of hurdles left before the technology hits the big time. For a start, the processors need to be more powerful. Unlike classical computers, which store data as either a 0 or a 1, quantum computers use qubits that save data as a mixture of these two states. Google’s quantum computer, called Sycamore, consisted of only 54 qubits – one of which didn’t work. For quantum computers to really come into their own, they will probably need thousands. But scaling up the number won’t be easy. Qubits must be isolated from vibrations as they can be easily disturbed, which can lead to computing errors down the line. There are many IBM is one firm in the race to build a practical quantum computer
SETH WENIG/AP/SHUTTERSTOCK
HOW much of a person’s career success is the result of chance? About half, depending on what field you’re in. Roberta Sinatra at the IT University of Copenhagen, Denmark, and her colleagues set out to measure what role luck and individual ability play in the success of creative works, including films, songs, books and scientific research papers. They used this as a proxy for career success. The researchers looked at works from more than 4 million people across the publishing, film and music industries, as well as 15 scientific fields. In each career there was a slightly different way of quantifying impact. For example, for movies and books they looked at the number of online reviews. By looking at the random fluctuations in the timing and magnitude of successful work, the team was able to come up with a crude estimate of luck different careers typically involve, using a measure called a randomness index, R. An entirely luck-based activity such as roulette would have an R score of 1, for example (arxiv.org/ abs/1909.07956). Luck appeared to have a relatively consistent effect across all the fields they studied, with a maximum difference of just 5 per cent. In the music industry, electronic music artists needed the most luck (0.546) and classical musicians the least (0.507), while in the film industry movie producers needed the most luck (0.545). Within science, success in astronomy involved the most luck (0.55) while computer science was associated with the least (0.517). The aim was to create a model of the ups and downs of success within a career, says Sinatra. The differences in luck between industries should be taken with a grain of salt, she says. ❚
competing ideas on how best to do this. As well as Google, firms including IBM, Microsoft and Intel are all looking at how to advance the technology. Also on the quantum computer to-do list is error correction. Classical computers have mechanisms to make sure that when little mistakes happen they are automatically rectified. The same will be needed for quantum computers, especially considering the delicate nature of qubits.
53
The number of (working) qubits in Google’s quantum computer
In 2016, a team at Yale University showed that error correction is possible with at least one form of qubit, although not the type used by Google. The challenge now is to build a quantum computer that has both quantum supremacy and error-correcting abilities. The final and perhaps most important next step is to actually do something useful. Google’s quantum computer tackled what is known as a
random circuit sampling problem. In such a task, after a series of calculations, each qubit outputs a 1 or 0. The aim is to calculate the probability of each possible outcome occurring. Google says Sycamore was able to find the answer in just a few minutes – a task it estimates would take 10,000 years on the most powerful supercomputer. Although that is impressive, there is no practical use for it. Google’s claim to quantum supremacy came via a paper published online and removed shortly afterwards. The company has yet to make any public statement on it. “We shouldn’t get too carried away with this,” says Ciarán Gilligan-Lee at University College London. This is an important step for quantum computing, but there’s still a long way to go, he says. The hope is that quantum computers could eventually help revolutionise our understanding of fields such as chemistry and material science by performing simulations that are too complex for classical computers. “There are certain quantities that you’d like to know, that you can’t easily learn from experiment and can’t calculate with supercomputers today. This is where quantum computers can help,” says Scott Aaronson at the University of Texas at Austin. This could eventually lead to breakthroughs in how we make fertilisers for food production or in improving the efficiency of energy transmission. There is a risk that quantum computers could be used to crack some forms of encryption that keep the internet secure. However, people are already working on alternative forms of encryption that would be harder to break. ❚ 5 October 2019 | New Scientist | 15
Analysis Computing
Half of your career success may be down to luck
What next for quantum computers? Google appears to have reached “quantum supremacy”, but there is still a long way to go before the technology is useful, reports Chelsea Whyte
Donna Lu
QUANTUM computing is now ready to go – or is it? Google appears to have reached an impressive milestone known as quantum supremacy, where a quantum computer is able to perform a calculation that is practically impossible for a classical one. But there are plenty of hurdles left before the technology hits the big time. For a start, the processors need to be more powerful. Unlike classical computers, which store data as either a 0 or a 1, quantum computers use qubits that save data as a mixture of these two states. Google’s quantum computer, called Sycamore, consisted of only 54 qubits – one of which didn’t work. For quantum computers to really come into their own, they will probably need thousands. But scaling up the number won’t be easy. Qubits must be isolated from vibrations as they can be easily disturbed, which can lead to computing errors down the line. There are many IBM is one firm in the race to build a practical quantum computer
SETH WENIG/AP/SHUTTERSTOCK
HOW much of a person’s career success is the result of chance? About half, depending on what field you’re in. Roberta Sinatra at the IT University of Copenhagen, Denmark, and her colleagues set out to measure what role luck and individual ability play in the success of creative works, including films, songs, books and scientific research papers. They used this as a proxy for career success. The researchers looked at works from more than 4 million people across the publishing, film and music industries, as well as 15 scientific fields. In each career there was a slightly different way of quantifying impact. For example, for movies and books they looked at the number of online reviews. By looking at the random fluctuations in the timing and magnitude of successful work, the team was able to come up with a crude estimate of luck different careers typically involve, using a measure called a randomness index, R. An entirely luck-based activity such as roulette would have an R score of 1, for example (arxiv.org/ abs/1909.07956). Luck appeared to have a relatively consistent effect across all the fields they studied, with a maximum difference of just 5 per cent. In the music industry, electronic music artists needed the most luck (0.546) and classical musicians the least (0.507), while in the film industry movie producers needed the most luck (0.545). Within science, success in astronomy involved the most luck (0.55) while computer science was associated with the least (0.517). The aim was to create a model of the ups and downs of success within a career, says Sinatra. The differences in luck between industries should be taken with a grain of salt, she says. ❚
competing ideas on how best to do this. As well as Google, firms including IBM, Microsoft and Intel are all looking at how to advance the technology. Also on the quantum computer to-do list is error correction. Classical computers have mechanisms to make sure that when little mistakes happen they are automatically rectified. The same will be needed for quantum computers, especially considering the delicate nature of qubits.
53
The number of (working) qubits in Google’s quantum computer
In 2016, a team at Yale University showed that error correction is possible with at least one form of qubit, although not the type used by Google. The challenge now is to build a quantum computer that has both quantum supremacy and error-correcting abilities. The final and perhaps most important next step is to actually do something useful. Google’s quantum computer tackled what is known as a
random circuit sampling problem. In such a task, after a series of calculations, each qubit outputs a 1 or 0. The aim is to calculate the probability of each possible outcome occurring. Google says Sycamore was able to find the answer in just a few minutes – a task it estimates would take 10,000 years on the most powerful supercomputer. Although that is impressive, there is no practical use for it. Google’s claim to quantum supremacy came via a paper published online and removed shortly afterwards. The company has yet to make any public statement on it. “We shouldn’t get too carried away with this,” says Ciarán Gilligan-Lee at University College London. This is an important step for quantum computing, but there’s still a long way to go, he says. The hope is that quantum computers could eventually help revolutionise our understanding of fields such as chemistry and material science by performing simulations that are too complex for classical computers. “There are certain quantities that you’d like to know, that you can’t easily learn from experiment and can’t calculate with supercomputers today. This is where quantum computers can help,” says Scott Aaronson at the University of Texas at Austin. This could eventually lead to breakthroughs in how we make fertilisers for food production or in improving the efficiency of energy transmission. There is a risk that quantum computers could be used to crack some forms of encryption that keep the internet secure. However, people are already working on alternative forms of encryption that would be harder to break. ❚ 5 October 2019 | New Scientist | 15