An experiment which could allow scientists to control millions of qubits at the same time was a success, although “there are engineering challenges to resolve before processors with a million qubits can be made”, they add.
Scientists from the University of New South Wales in Sydney, Australia, have announced the discovery of a major breakthrough in quantum computing.
To date, quantum scientists and computer engineers have only been able to use proof-of-concept models of quantum processors that work with just a few spin qubits, the quantum equivalent of a bit.
Now, new research published in the journal Science Advances has identified a technique which the researchers claim will enable them to control millions of these qubits.
The team considers their design the “missing jigsaw piece” in quantum computer architecture.
In a traditional computer, a bit – the single unit of information, either a 0 or a 1 – is stored in the electronic circuit of the computer itself, specifically in the capacitor of a memory cell, with the value depending on whether the capacitor is charged or discharged.
Spin qubit quantum computers replace this capacitor with a single quantum particle – the electron – and its “spin” value.
Dr Jarryd Play, a researcher at UNSW, explained: “Up until this point, controlling electron spin qubits relied on us delivering microwave magnetic fields by putting a current through a wire right beside the qubit.
“This poses some real challenges if we want to scale up to the millions of qubits that a quantum computer will need to solve globally significant problems, such as the design of new vaccines.
“First off, the magnetic fields drop off really quickly with distance, so we can only control those qubits closest to the wire.
“That means we would need to add more and more wires as we brought in more and more qubits, which would take up a lot of real estate on the chip.”
The issue is that these chips need to operate at extremely cold temperatures, below -270C, and introducing more wires would compromise the temperature of the chip and interfere with the reliability of the qubit.
“So we come back to only being able to control a few qubits with this wire technique,” Dr Pla said.
The breakthrough came in redesigning the entire structure of a chip. Instead of having thousands of control wires running across the thumbnail-sized piece of silicon, the team generated a magnetic field from above the chip which can manipulate all of the qubits simultaneously.
This had first been proposed in the 1990s, but the new research is the first practical way to achieve this.
“First we removed the wire next to the qubits and then came up with a novel way to deliver microwave-frequency magnetic control fields across the entire system. So in principle, we could deliver control fields to up to four million qubits,” said Dr Pla.
The researchers then added a new component above the silicon chip, a crystal prism called a dielectric resonator, which can be used to focus the wavelength of microwaves down into a smaller size.
“The dielectric resonator shrinks the wavelength down below one millimetre, so we now have a very efficient conversion of microwave power into the magnetic field that controls the spins of all the qubits.
“There are two key innovations here. The first is that we don’t have to put in a lot of power to get a strong driving field for the qubits, which crucially means we don’t generate much heat. The second is that the field is very uniform across the chip, so that millions of qubits all experience the same level of control.”
The team’s experiments which could allow them to control millions of qubits at the same time was a success, although “there are engineering challenges to resolve before processors with a million qubits can be made”, Dr Pla added.
COVID-19: Facebook removes Chinese-backed network of fake accounts spreading coronavirus disinformation
The false profiles, with links to Chinese-backed agencies, originated and spread false claims the US pressured scientists to blame China for COVID-19.
Facebook has removed hundreds of fake accounts linked to a campaign by China to spread unfounded claims about the pandemic.
The bogus profiles originated claims the US pressured scientists to blame China for COVID-19.
An investigation found these claims were amplified by employees of Chinese state-run companies, soon becoming the subject of domestic news headlines.
“In effect it worked like an online hall of mirrors, endlessly reflecting the original fake persona and its anti-US disinformation,” Ben Nimmo, who leads investigations into disinformation at Meta, the parent company of Facebook and Instagram, said.
The social media company said one of the accounts belonged to a fictitious Swiss biologist named Wilson Edwards.Advertisement
In July, when the operation began, Mr Wilson’s profile claimed US officials were using “enormous pressure and even intimidation” to get scientists to back calls for renewed investigations into the origin of coronavirus.
Within hours, hundreds of other accounts – some only created only that day – began liking, reposting or linking to the post.
Many of the accounts were later found to be fake, with some of the users posing as westerners and others using likely fabricated profile photos.
Facebook said it found links between the accounts and a tech firm based in Chengdu, China, as well as to overseas employees of Chinese infrastructure companies.
Within a week of the initial post, large media outlets in China were reporting on the claims as if they had been made by a real scientist.
The operation was exposed when Swiss authorities announced in August that they had no record of any biologist with that name.
In all, Meta removed about 600 accounts on Facebook and Instagram that were linked to the network.
China’s Ministry of Foreign Affairs has said in the past that the country’s government does not employ trickery on social media.
Coronavirus emerged in Wuhan, China in December 2019 before spreading around the world.
Different governments, experts and organisations, including the US, have suggested the virus may have come from a lab leak in the city – a claim China vehemently denies.
That theory was dismissed by a team led by the World Health Organisation (WHO) that spent four weeks in and around Wuhan in January and February.
However, their report, released in March, was criticised for not finding sufficient evidence to discard the idea – and the WHO’s director-general has since said there had been a “premature push” to rule out the lab leak theory.
The US carried out their own investigation and came to the same conclusion.
Meta: UK competition regulator tells Facebook owner to sell GIF library Giphy
The investigation into the acquisition has been acrimonious, with Meta previously being fined £50m by the CMA for deliberately refusing to comply with the regulator’s inquiries.
Facebook’s owner Meta has been issued a legally binding order to sell the GIF library Giphy after an investigation found the takeover “could harm social media users and UK advertisers”.
The Competition and Markets Authority (CMA) launched an in-depth investigation into the deal in April after raising a number of concerns. It subsequently warned of the potential forced sale in August.
Giphy – a website for making and sharing animated images, known as GIFs – was acquired by Facebook (now Meta) in May last year to integrate the GIFs with Instagram, but the CMA has now ordered the acquisition to be unravelled.
Sky News understands Facebook intends to appeal the CMA’s decision. It has four weeks to do so and the appeal would go to a the Competition Appeal Tribunal, which is independent of the CMA.
Meta could potentially challenge that ruling in the UK courts, but only on points of law.Advertisement
Stuart McIntosh, who chaired the independent inquiry into the acquisition, said: “The tie-up between Facebook and Giphy has already removed a potential challenger in the display advertising market.
“Without action, it will also allow Facebook to increase its significant market power in social media even further, through controlling competitors’ access to Giphy GIFs.
“By requiring Facebook to sell Giphy, we are protecting millions of social media users and promoting competition and innovation in digital advertising,” Mr McIntosh explained.
The investigation into the acquisition has seen points of acrimony, with Meta being fined a record £50m by the CMA for deliberately refusing to comply with the regulator’s inquiries.
Meta argued that it has been in compliance with the competition watchdog’s primary orders at all times.
At the time of the fine, the company complained that the CMA delayed for seven months a request to amend these orders which was eventually agreed in what the company described as nearly an identical manner to what had been requested.
When Facebook first merged with Giphy it terminated the image library’s advertising services, “removing an important source of potential competition” according to the CMA.
This was considered “particularly concerning given that Facebook controls nearly half of the £7 billion display advertising market in the UK”.
However in Meta’s response to the preliminary findings, the social media giant described the acquisition as a simple vertical merger and said that Giphy was financially troubled and suggested that its attempts to monetise its GIF library for display advertising were unsuccessful.
“If GIF paid alignments were the promising business model that the CMA believes they are, then one would expect to encounter them in the real-world at scale… Yet that is not the case,” the response stated.
According to the regulator, the acquisition potentially also enabled the social media giant to change the terms of access to the GIF library for its competitors.
“For example, Facebook could require Giphy customers, such as TikTok, Twitter and Snapchat, to provide more user data in order to access Giphy GIFs.
“Such actions could increase Facebook’s market power, which is already significant,” the regulator said.
In its review of the merger, the CMA said it risked entrenching Meta’s market dominance, noting that its platforms (Facebook, Instagram, and WhatsApp) already accounted for 73% of all user time spent on social media in the UK.
A spokesperson for Meta said: “We disagree with this decision. We are reviewing the decision and considering all options, including appeal. Both consumers and Giphy are better off with the support of our infrastructure, talent, and resources.
“Together, Meta and Giphy would enhance Giphy’s product for the millions of people, businesses, developers and API partners in the UK and around the world who use Giphy every day, providing more choices for everyone.”
COVID-19: Mild and moderate cases during pregnancy doesn’t harm babies’ brains, finds study
Parents should be reassured, there is “no evidence that a maternal SARS-CoV-2 infection has any effect on the brain development of the unborn child” say scientists.
Mild and moderate coronavirus infections in pregnant women appear to have no effect on the brain of the developing foetus according to a new study.
Two years into the COVID-19 pandemic “there is evidence that pregnant women are more vulnerable” to the coronavirus, according to a study presented to the Radiological Society of North America (RSNA).
The new study aims to identify what the possible consequences are for the unborn child if the mother is infected during pregnancy, and to study the likelihood of the virus being passed on to the foetus.
“Women infected with SARS-CoV-2 during pregnancy are concerned that the virus may affect the development of their unborn child, as is the case with some other viral infections,” said Dr Sophia Stoecklein, senior author of the study.Advertisement
“So far, although there are a few reports of vertical transmission to the foetus, the exact risk and impact remain largely unclear,” added Dr Stoecklein, from the department of radiology at Ludwig Maximilian University of Munich.
“The aim of our study was to fill this gap in knowledge regarding the impact of a maternal SARS-CoV-2 infection on foetal brain development,” she added.
MRI scans were used to study 33 pregnant women who were infected with COVID-19 during their pregnancy, with the women roughly 28 weeks into the pregnancies at the time of the scan.
The scans were evaluated by radiologists with years of experience in foetal MRIs who found that the brain development in the assessed areas was age-appropriate in all of the children, with no findings indicating any infection affected the brains.
“In our study, there was no evidence that a maternal SARS-CoV-2 infection has any effect on the brain development of the unborn child,” Dr Stoecklein said. “This fact should help to reassure affected parents.”
But she cautioned that only mothers with mild to moderate symptoms who were not hospitalised were included in the study, meaning the impact of “severe infection on brain development in the foetus has not been conclusively determined”.