How do you make a qubit 10 times as stable? Dress it up for work

No joke. Electromagnetic fields could help achieve dream of quantum computing


Dressing qubits in an electromagnetic field can make them 10 times more stable and able to perform more calculations over time in future quantum computers, according to new research in Nature Nanotechnology.

Qubits - or quantum bits - hold information in quantum computers just like bits do in conventional computers. Instead of two states, 0 and 1, however, a qubit can occupy an infinite number of states as its quantum states are entangled with one another.

The mishmash of quantum states interacting with its environment means that its state changes over time. A property known as quantum coherence erodes over time and the relation between quantum states and the information it holds vanishes, making quantum computers tricky to use.

Researchers from the University of New South Wales (UNSW) and Keio University have increased qubit stability by "dressing" it with electromagnetic fields.

The research improves upon previous work by the Centre for Quantum Computation & Communication Technology (CQC2T) at UNSW as it uses a varying magnetic field. The new coherence time of 2.4 milliseconds - 10 times longer than what has been previously achieved by researchers at CQC2T with a standard qubit.

Andrea Morello, leader of the research team, said: "Our decade-long research program had already established the most long-lived quantum bit in the solid state, by encoding quantum information in the spin of a single phosphorus atom inside a silicon chip, placed in a static magnetic field.

“We have now implemented a new way to encode the information: we have subjected the atom to a very strong, continuously oscillating electromagnetic field at microwave frequencies, and thus we have 'redefined' the quantum bit as the orientation of the spin with respect to the microwave field."

The high frequency of the varying magnetic field makes it harder for noise oscillating at a different frequency to disturb the quantum system. It can also be controlled better. Researchers can tune the system like an FM radio by changing the frequency of the field, says the researcher.

“The 'undressed qubit' instead requires turning the amplitude of the control fields on and off, like an AM radio. In some sense, this is why the dressed qubit is more immune to noise: the quantum information is controlled by the frequency, which is rock-solid, whereas the amplitude can be more easily affected by external noise," Morello said.

Quantum computing is a competitive field with researchers racing ahead to improve the capabilities of quantum computers, promising to unleash the next generation of computers which are much faster and powerful. ®

Broader topics

Narrower topics


Other stories you might like

  • Lonestar plans to put datacenters in the Moon's lava tubes
    How? Founder tells The Register 'Robots… lots of robots'

    Imagine a future where racks of computer servers hum quietly in darkness below the surface of the Moon.

    Here is where some of the most important data is stored, to be left untouched for as long as can be. The idea sounds like something from science-fiction, but one startup that recently emerged from stealth is trying to turn it into a reality. Lonestar Data Holdings has a unique mission unlike any other cloud provider: to build datacenters on the Moon backing up the world's data.

    "It's inconceivable to me that we are keeping our most precious assets, our knowledge and our data, on Earth, where we're setting off bombs and burning things," Christopher Stott, founder and CEO of Lonestar, told The Register. "We need to put our assets in place off our planet, where we can keep it safe."

    Continue reading
  • Conti: Russian-backed rulers of Costa Rican hacktocracy?
    Also, Chinese IT admin jailed for deleting database, and the NSA promises no more backdoors

    In brief The notorious Russian-aligned Conti ransomware gang has upped the ante in its attack against Costa Rica, threatening to overthrow the government if it doesn't pay a $20 million ransom. 

    Costa Rican president Rodrigo Chaves said that the country is effectively at war with the gang, who in April infiltrated the government's computer systems, gaining a foothold in 27 agencies at various government levels. The US State Department has offered a $15 million reward leading to the capture of Conti's leaders, who it said have made more than $150 million from 1,000+ victims.

    Conti claimed this week that it has insiders in the Costa Rican government, the AP reported, warning that "We are determined to overthrow the government by means of a cyber attack, we have already shown you all the strength and power, you have introduced an emergency." 

    Continue reading
  • China-linked Twisted Panda caught spying on Russian defense R&D
    Because Beijing isn't above covert ops to accomplish its five-year goals

    Chinese cyberspies targeted two Russian defense institutes and possibly another research facility in Belarus, according to Check Point Research.

    The new campaign, dubbed Twisted Panda, is part of a larger, state-sponsored espionage operation that has been ongoing for several months, if not nearly a year, according to the security shop.

    In a technical analysis, the researchers detail the various malicious stages and payloads of the campaign that used sanctions-related phishing emails to attack Russian entities, which are part of the state-owned defense conglomerate Rostec Corporation.

    Continue reading
  • FTC signals crackdown on ed-tech harvesting kid's data
    Trade watchdog, and President, reminds that COPPA can ban ya

    The US Federal Trade Commission on Thursday said it intends to take action against educational technology companies that unlawfully collect data from children using online educational services.

    In a policy statement, the agency said, "Children should not have to needlessly hand over their data and forfeit their privacy in order to do their schoolwork or participate in remote learning, especially given the wide and increasing adoption of ed tech tools."

    The agency says it will scrutinize educational service providers to ensure that they are meeting their legal obligations under COPPA, the Children's Online Privacy Protection Act.

    Continue reading
  • Mysterious firm seeks to buy majority stake in Arm China
    Chinese joint venture's ousted CEO tries to hang on - who will get control?

    The saga surrounding Arm's joint venture in China just took another intriguing turn: a mysterious firm named Lotcap Group claims it has signed a letter of intent to buy a 51 percent stake in Arm China from existing investors in the country.

    In a Chinese-language press release posted Wednesday, Lotcap said it has formed a subsidiary, Lotcap Fund, to buy a majority stake in the joint venture. However, reporting by one newspaper suggested that the investment firm still needs the approval of one significant investor to gain 51 percent control of Arm China.

    The development comes a couple of weeks after Arm China said that its former CEO, Allen Wu, was refusing once again to step down from his position, despite the company's board voting in late April to replace Wu with two co-chief executives. SoftBank Group, which owns 49 percent of the Chinese venture, has been trying to unentangle Arm China from Wu as the Japanese tech investment giant plans for an initial public offering of the British parent company.

    Continue reading
  • SmartNICs power the cloud, are enterprise datacenters next?
    High pricing, lack of software make smartNICs a tough sell, despite offload potential

    SmartNICs have the potential to accelerate enterprise workloads, but don't expect to see them bring hyperscale-class efficiency to most datacenters anytime soon, ZK Research's Zeus Kerravala told The Register.

    SmartNICs are widely deployed in cloud and hyperscale datacenters as a means to offload input/output (I/O) intensive network, security, and storage operations from the CPU, freeing it up to run revenue generating tenant workloads. Some more advanced chips even offload the hypervisor to further separate the infrastructure management layer from the rest of the server.

    Despite relative success in the cloud and a flurry of innovation from the still-limited vendor SmartNIC ecosystem, including Mellanox (Nvidia), Intel, Marvell, and Xilinx (AMD), Kerravala argues that the use cases for enterprise datacenters are unlikely to resemble those of the major hyperscalers, at least in the near term.

    Continue reading

Biting the hand that feeds IT © 1998–2022