Quantum Campus shares the latest in quantum science and technology. Read by more than 1,400 researchers, we publish on Fridays and are always looking for news from across the country. Want to see your work featured? Submit your ideas to the editor.

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The University of Science and Technology of China published details of a 105-qubit quantum processor last week. In his assessment of the chip in APS’s Physics, Barry Sanders of the Institute for Quantum Science and Technology at the University of Calgary described it as having performance similar to Google’s Willow, “indicating a neck-and-neck race between the two groups.”

The team reported high fidelity operations with single-qubit gates at 99.9 percent, two-qubit gates at 99.6 percent, and readout fidelity at 99.13%.

Details were published in Physical Review Letters.

Further critique of Majorana 1

Nature published a story on concerns from a researcher at the University of St. Andrews about the topological gap protocol used by Microsoft to assess performance of its Majorana 1 chip and its claim that it had produced Majoranas. St. Andrews’ Henry Legg also criticized the variable external conditions allowed by the Microsoft team, as well as differences between the new details shared by Microsoft in February and an earlier paper they published in Physical Review B in 2023.

Microsoft, meanwhile, claimed that Legg had created a “false straw man,” and Nature, which published the most recent Microsoft paper, said that the journal is aware of concerns about the topological gap protocol and that “the validity of the Nature paper was not affected by those concerns.”

Read the Nature story and a preprint of Legg’s critique. The Register covered other researchers’ criticisms of Majorana 1 this week, along with a response from Microsoft.

Excitons using nanodots

Scientists at Penn State and Université Paris-Saclay showed controllable light emission from spatially confined two-dimensional nanodots for the first time. They embedded monolayer molybdenum diselenide nanodots of varying sizes in a monolayer tungsten diselenide matrix.

The results showed that nanodots less than 10 nanometers wide drove quantum confinement and produced excitons at the materials’ interface.

This work was published in ACS Photonics.

Q-Cat

IEEE Spectrum talked to Amanda Stein, CEO of Q-Cat, about using nitrogen-vacancy center defects in diamonds for future quantum sensors. The company is looking at applying these sensors in rugged environments like the space and energy industries, as well as in assessing high-value artwork.

Read the interview in IEEE Spectrum.

Quickbits

• University of Arizona receives $2 million to study error correction

• Single-photon source for efficient linear optical quantum computing (Nature Photonics)

• D-Wave demonstrates quantum supremacy on set of materials science calculations (Science)

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