Quantum Computing News and Discussions

[weatheriscool]

Researchers certify genuine quantum behavior in computers with up to 73 qubits

by C. Huygelen, Leiden University
https://phys.org/news/2025-07-certify-g ... ubits.html

Can you prove whether a large quantum system truly behaves according to the weird and wonderful rules of quantum mechanics—or if it just looks like it does? In a new study, physicists from Leiden, Beijing and Hangzhou found the answer to this question.

You could call it a "quantum lie detector": Bell's test designed by famous physicist John Bell. This test shows whether a machine, like a quantum computer, is truly using quantum effects or just mimics them.

As quantum technologies become more mature, ever more stringent tests of quantumness become necessary. In this new study, the researchers took things to the next level, testing Bell correlations in systems with up to 73 qubits—the basic building blocks of a quantum computer.

The study involved a global team: theoretical physicists Jordi Tura, Patrick Emonts, Ph.D. candidate Mengyao Hu from Leiden University, together with colleagues from Tsinghua University (Beijing) and experimental physicists from Zhejiang University (Hangzhou). The work is published in the journal Physical Review X.

[weatheriscool]

Quantum internet moves closer as researchers teleport light-based information

by Ingrid Fadelli, Phys.org
https://phys.org/news/2025-07-quantum-i ... based.html

Quantum teleportation is a fascinating process that involves transferring a particle's quantum state to another distant location, without moving or detecting the particle itself. This process could be central to the realization of a so-called "quantum internet," a version of the internet that enables the safe and instant transmission of quantum information between devices within the same network.

Quantum teleportation is far from a recent idea, as it was experimentally realized several times in the past. Nonetheless, most previous demonstrations utilized frequency conversion rather than natively operating in the telecom band.

[weatheriscool]

https://www.millenniumpost.in/sundaypos ... eap-614945

[firestar464]

they recycled old news

https://newatlas.com/computers/jiuzhang ... supremacy/

[weatheriscool]

[weatheriscool]

[weatheriscool]

IBM’s New Decoder Could Kickstart Real-World Quantum Computing
A new way of finding and correcting quantum problems leads to 'orders of magnitude' fewer errors.
By Graham Templeton August 8, 2025

A new publication from IBM has announced a step towards overcoming one of the biggest fundamental problems with quantum computers: they often just don’t work right.

Quantum computers are inherently hard machines to make. From the difficulty of entangling the qubits in the first place to the errors inserted by the difficulty of keeping them entangled, at any given moment, it really does seem like quantum computers are trying not to work.

In an effort to maintain entanglement, we have historically had big, shielded boxes and networking lines that protect the qubits from outside disturbance. You can also try networking with photons, creating laser-based quantum networks that exploit light’s weak interactions with air.

But this inevitably is not enough. Qubits are too delicate for easy use, and the near-constant problems they encounter make quantum computing unavoidably error-prone.

https://www.extremetech.com/science/ibm ... -computing

[weatheriscool]

[weatheriscool]

[weatheriscool]

Room Temperature Diamond Integrated Chip Quantum Accelerators Installed At Oak Ridge National Lab
September 3, 2025 by Brian Wang

https://www.nextbigfuture.com/2025/09/r ... l-lab.html
Quantum Brilliance’s is developing diamond quantum accelerators containing >50 qubits that outperform CPUs/GPUs of comparable size, weight and power in important applications within the next 5 years. In 2021, Quantum Brilliance will deliver its first Quantum Development Kits (QDKs), which will contain up to 5 qubits in a 19-inch rack-mountable unit. These QDKs will support benchmarking, hardware and software integration with classical computing systems, accelerator co-design and application discovery activities with Quantum Brilliance’s customers and R&D partners. Over the next five years, the QDKs will be progressively upgraded with more qubits, reduced in size and ruggedized, through the implementation of atomically-precise diamond fabrication and on-chip control system integration.

Oak Ridge National Lab installed Quantum Brilliance computer system at the Oak Ridge Leadership Computing Facility. Lab staff will use ORNL’s first on-site, commercial quantum computer cluster to explore ways to integrate this emerging technology into classical high-performance computing infrastructures and tap its potential for massive computational power gains.

Quantum Brilliance believe these diamond integrated chips can be mass produced in the millions and can work along side regular chips as useful accelerators and sensors. They could also have versions that can work as global positioning without using satellites.

[weatheriscool]

[weatheriscool]

Like talking on the telephone': Quantum computing engineers get atoms chatting long distance
https://phys.org/news/2025-09-quantum-a ... tance.html
by University of New South Wales

UNSW engineers have made a significant advance in quantum computing: they created 'quantum entangled states'—where two separate particles become so deeply linked they no longer behave independently—using the spins of two atomic nuclei. Such states of entanglement are the key resource that gives quantum computers their edge over conventional ones.

The research is published in the journal Science, and is an important step toward building large-scale quantum computers—one of the most exciting scientific and technological challenges of the 21st century.

[weatheriscool]

[weatheriscool]

[weatheriscool]

[wjfox]

Caltech builds record-breaking 6,100-qubit array

Researchers at Caltech have assembled the world's largest array of atomic qubits – 6,100 in total. Although the system is not yet a fully programmable quantum computer, the proof-of-concept shows what might be possible in the next year or two.

30th September 2025

Quantum computing is all about qubits, the quantum equivalent of classical bits. The more qubits you have, and the more reliably they interact, the more powerful your machine becomes.

In 2023, Atom Computing grabbed headlines by unveiling a 1,180-qubit device. That system, based on nuclear spin qubits, was widely regarded as the largest programmable quantum computer at the time. It allowed entanglement and operations across the entire register of qubits, representing a genuine step forward in practical use.

Now Caltech, led by physicist Manuel Endres, reports an array containing 6,100 atomic qubits trapped in optical tweezers. Their new paper in Nature describes an architecture with remarkable performance: qubits that stay coherent for more than 12 seconds, gate fidelities of 99.98%, and imaging accuracy above 99.99%. On sheer numbers and stability, nothing else comes close.

"This is an exciting moment for neutral-atom quantum computing," says Manuel Endres, Professor of Physics at Caltech. "We can now see a pathway to large, error-corrected quantum computers. The building blocks are in place."

Read more: https://www.futuretimeline.net/blog/202 ... -array.htm



This image shows 6,100 caesium atoms trapped by highly focused laser beams called "optical tweezers". The width of the circle is about one millimetre. Credit: Caltech/Endres Lab

[weatheriscool]

Individual electrons trapped and controlled above 1 K, easing cooling limits for quantum computing
https://phys.org/news/2025-10-individua ... imits.html
by EeroQ

Researchers from EeroQ, the quantum computing company pioneering electron-on-helium technology, have published a paper, titled "Sensing and Control of Single Trapped Electrons Above 1 Kelvin," in Physical Review X that details a significant milestone: the first demonstration of controlling and detecting individual electrons trapped on superfluid helium at temperatures above 1 Kelvin. This work was achieved using on-chip superconducting microwave circuits, a method compatible with existing quantum hardware.

Quantum computers today typically require operation at ultra-low temperatures near 10 millikelvin, creating severe challenges in scaling due to heat dissipation. By showing that individual electrons can be trapped and controlled at temperatures more than 100 times higher (above 1 Kelvin), EeroQ's results open a new pathway toward larger and more practical quantum processors.

The findings also validate long-standing theoretical predictions that electrons on helium can provide exceptionally pure and long-lived qubits, while reducing the extreme cooling demands that limit other approaches.

[wjfox]

‘Nightmare’ calculation may be too tricky for even quantum computers

Quantum computers hold great potential for solving many problems more quickly or efficiently than conventional computers, but researchers are starting to identify where they could falter

By Karmela Padavic-Callaghan
17 October 2025

Researchers have identified a “nightmare scenario” calculation related to exotic types of quantum matter that would be impossible to solve, even for a very efficient quantum computer.

Without the complexity of quantum states of matter, determining the phase of a material can be relatively simple. Take water, for example – it is straightforward to tell whether it is in a solid or liquid phase. The quantum version of this task, however, can be a lot more daunting. Thomas Schuster at the California Institute of Technology and his colleagues have now proven identifying quantum phases of matter can get too difficult even for quantum computers.

They mathematically analysed a scenario where a quantum computer is presented with a set of measurements about a quantum state of an object and has to identify its phase. Schuster says this is not always an impossible problem, but his team proved for a substantial portion of quantum phases of matter – the more exotic relatives of liquid water and ice, such as “topological” phases that feature odd electric currents – a quantum computer may need to calculate for an impossibly long time. The situation is like the worst version of a lab experiment where identifying the properties of a sample would require keeping an instrument on for billions or trillions of years.

This doesn’t make quantum computers practically obsolete for this task. Schuster says these phases are unlikely to show up in actual experiments with materials or quantum computers – they are more of a diagnostic for where our understanding of quantum computation is currently lacking than an imminent practical threat. “They’re like a nightmare scenario that would be very bad if it appears. It probably doesn’t appear, but we should understand it better,” he says.

Bill Fefferman at the University of Chicago in Illinois says this course of study opens intriguing questions about what computers can do in general. “This may be saying something about the limits of computation more broadly, that despite attaining dramatic speed-ups for certain specific tasks, there will always be tasks that are still too hard even for efficient quantum computers,” he says.

https://www.newscientist.com/article/25 ... computers/

[weatheriscool]

[weatheriscool]

Google Researchers Make Quantum Computing Breakthrough With Willow Chip
Verifiable quantum advantage "Quantum Echoes" brings the team closer to Milestone 3.

The research team working towards quantum computing at Google Quantum AI announced a major step forward this week in the journal Nature. Thanks to Willow, a quantum chip that features a 105-qubit array and is significantly better at suppressing errors than previous hardware, the team can run a verifiable quantum advantage.

According to the researchers, the computer running the Willow quantum chip is 13,000 times faster than a classical supercomputer. The idea behind a quantum advantage is that it marks the point at which a quantum computer is capable of solving a real-world problem that classical computers can't complete in a reasonable timeframe (or at all). In this case, the team noted that it can compute a molecule, though not necessarily a complex one.

https://www.extremetech.com/computing/g ... illow-chip