Nav: Home

Imaging of exotic quantum particles as building blocks for quantum computing

July 29, 2019

Researchers at the University of Illinois at Chicago, in collaboration with their colleagues at the University of Hamburg in Germany, have imaged an exotic quantum particle -- called a Majorana fermion -- that can be used as a building block for future qubits and eventually the realization of quantum computers. Their findings are reported in the journal Science Advances.

More than 50 years ago, Gordon Moore, the former CEO of Intel, observed that the number of transistors on a computer chip doubles every 18 to 24 months. This trend, now known as Moore's Law, has continued to the present day, leading to transistors that are only a few nanometers -- one-billionth of a meter -- in size. At this scale, the classical laws of physics, which form the basis on which our current computers work, cease to function, and they are replaced by the laws of quantum mechanics. Making transistors even smaller, which has been used in the past to increase computing speed and data storage, is, therefore, no longer possible.

Unless researchers can figure out how to use quantum mechanics as the new foundation for the next generation of computers.

This was the basic idea formulated in 1982 by Richard Feynman, one of the most influential theoretical physicists of the 20th century. Rather than using classical computer bits that store information encoded in zeros and ones, one would devise "quantum bits" -- or qubits for short -- that would utilize the laws of quantum mechanics to store any number between 0 and 1, thereby exponentially increasing computing speed and leading to the birth of quantum computers.

"Usually, when you drop your cell phone, it doesn't erase the information on your phone," said Dirk Morr, professor of physics at UIC and corresponding author on the paper. "That's because the chips on which information is stored in bits of ones and zeros are fairly stable. It takes a lot of messing around to turn a one into a zero and vice versa. In quantum computers, however, because there is an infinite number of possible states for the qubit to be in, information can get lost much more easily."

To form more robust and reliable qubits, researchers have turned to Majorana fermions -- quantum particles that occur only in pairs.

"We only need one Majorana fermion per qubit, and so we have to separate them from each other," Morr said.

By building qubits from a pair of Majorana fermions, information can be reliably encoded, as long as the Majoranas remain sufficiently far apart.

To achieve this separation, and to "image" a single Majorana fermion, it is necessary to create a "topological superconductor" -- a system that can conduct currents without any energy losses, and at the same time, is tied into a "topological knot."

"This topological knot is similar to the hole in a donut: you can deform the donut into a coffee mug without losing the hole, but if you want to destroy the hole, you have to do something pretty dramatic, such as eating the donut," Morr said.

To build topological superconductors, Morr's colleagues at the University of Hamburg placed an island of magnetic iron atoms, only tens of nanometers in diameter, on the surface of rhenium, a superconductor. Morr's group had predicted that by using a scanning tunneling microscope, one should be able to image a Majorana fermion as a bright line along the edge of the island of iron atoms. And this is exactly what the experimental group observed.

"Being able to actually visualize these exotic quantum particles takes us another step closer to building robust qubits, and ultimately quantum computers," Morr said. "The next step will be to figure out how we can quantum engineer these Majorana qubits on quantum chips and manipulate them to obtain an exponential increase in our computing power. This will allow us to address many problems we face today, from fighting global warming and forecasting earthquakes to alleviating traffic congestion through driverless cars and creating a more reliable energy grid."
Eric Mascot and Sagen Cocklin of the University of Illinois at Chicago; Alexandra Palacio-Morales, Howon Kim and Roland Wiesendanger of the University of Hamburg and Stephan Rachel of the University of Melbourne are co-authors on the paper.

This work was supported by the European Research Council Advanced Grant ASTONISH (project no. 338802) and ADMIRE (project no. 786020); the Alexander von Humboldt Foundation; the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under award no. DE-FG02-05ER46225; and the Australian Research Council (FT180100211).

University of Illinois at Chicago

Related Science Articles:

75 science societies urge the education department to base Title IX sexual harassment regulations on evidence and science
The American Educational Research Association (AERA) and the American Association for the Advancement of Science (AAAS) today led 75 scientific societies in submitting comments on the US Department of Education's proposed changes to Title IX regulations.
Science/Science Careers' survey ranks top biotech, biopharma, and pharma employers
The Science and Science Careers' 2018 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.
Science in the palm of your hand: How citizen science transforms passive learners
Citizen science projects can engage even children who previously were not interested in science.
Applied science may yield more translational research publications than basic science
While translational research can happen at any stage of the research process, a recent investigation of behavioral and social science research awards granted by the NIH between 2008 and 2014 revealed that applied science yielded a higher volume of translational research publications than basic science, according to a study published May 9, 2018 in the open-access journal PLOS ONE by Xueying Han from the Science and Technology Policy Institute, USA, and colleagues.
Prominent academics, including Salk's Thomas Albright, call for more science in forensic science
Six scientists who recently served on the National Commission on Forensic Science are calling on the scientific community at large to advocate for increased research and financial support of forensic science as well as the introduction of empirical testing requirements to ensure the validity of outcomes.
World Science Forum 2017 Jordan issues Science for Peace Declaration
On behalf of the coordinating organizations responsible for delivering the World Science Forum Jordan, the concluding Science for Peace Declaration issued at the Dead Sea represents a global call for action to science and society to build a future that promises greater equality, security and opportunity for all, and in which science plays an increasingly prominent role as an enabler of fair and sustainable development.
PETA science group promotes animal-free science at society of toxicology conference
The PETA International Science Consortium Ltd. is presenting two posters on animal-free methods for testing inhalation toxicity at the 56th annual Society of Toxicology (SOT) meeting March 12 to 16, 2017, in Baltimore, Maryland.
Citizen Science in the Digital Age: Rhetoric, Science and Public Engagement
James Wynn's timely investigation highlights scientific studies grounded in publicly gathered data and probes the rhetoric these studies employ.
Science/Science Careers' survey ranks top biotech, pharma, and biopharma employers
The Science and Science Careers' 2016 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.
Three natural science professors win TJ Park Science Fellowship
Professor Jung-Min Kee (Department of Chemistry, UNIST), Professor Kyudong Choi (Department of Mathematical Sciences, UNIST), and Professor Kwanpyo Kim (Department of Physics, UNIST) are the recipients of the Cheong-Am (TJ Park) Science Fellowship of the year 2016.
More Science News and Science Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at     You can read The Transition Integrity Project's report here.