| Tiny quantum computing processors built from silicon have finally surpassed 99 percent fidelity in certain logic operations (“gates”). Quantum computers store information in the quantum state of a physical system (in this case, two silicon qubits) then manipulate the quantum state to perform a calculation in a manner that isn’t possible on a classical computer. | |
| Fidelity is a measure of how close the final quantum state of the real-life qubits is to the ideal case. If the fidelity of logic gates is too low, calculations will fail because errors will accumulate faster than they can be corrected. The threshold for fault-tolerant quantum computing is over 99 percent. | |
| Three research groups demonstrated more than 99 percent fidelity for “if-then” logic gates between two silicon qubits (Nature, “Precision tomography of a three-qubit donor quantum processor in silicon”). This required precisely measuring failure rates, identifying the nature and cause of the errors, and fine-tuning the devices. |
| The researchers used a technique called gate set tomography to achieve this in two of the three experiments. The technique combined the results of many separate experiments to create a detailed snapshot of the errors in each logic gate. | |
| The researchers were able to make a precise determination of the error generated by different sources and fine-tune the gates to achieve error rates below 1 percent. | |
| Quantum computing may be able to solve certain problems, such as predicting the behavior of new molecules, far faster than today’s computers. To do so, researchers must build qubits, engineer precise couplings between them, and scale up systems to thousands or millions of qubits. | |
| Researchers expect qubits made of silicon to scale up better than the qubits used in today’s testbed quantum computers, which rely on either trapped ions or superconducting circuits. | |
| Achieving high-fidelity logic gates opens the door to silicon-based testbed quantum computers. It also demonstrates the power of detailed error characterization to help users pinpoint error modes then work around or eliminate them. | |
| Qubits – protected, controllable 2-state quantum systems – lie at the heart of quantum computing. Quantum computing processors are built by assembling an array of at least two (and hopefully someday thousands or millions) of qubits, with an integrated control system that can perform logic gates on each qubit and between pairs of qubits. Their performance and capability are limited by errors in the logic gates. | |
| High-fidelity gates have low error rates. Once the error rate is less than a certain threshold – which scientists believe to be about 1 percent – quantum error correction can, in principle, reduce it even further. Beating this threshold in laboratory experiments is a major milestone for any qubit technology. | |
| What kinds of errors are occurring is also a big deal for quantum error correction. Some errors are easier to eliminate or correct; others may be fatal. Quantum computing researchers from the Department of Energy (DOE)-funded Quantum Performance Laboratory worked with Australian experimental physicists to design a new kind of gate set tomography customized to a 3-qubit silicon qubit processor. They used it to measure the rates of 240 distinct types of possible errors on each of six logic gates. Of those possible errors, 95 percent did not occur in the experiments, and the remaining errors added up to less than 1 percent infidelity. | |
| Research groups in Japan and the Netherlands reported similar results simultaneously, with the Dutch group also using the DOE-funded pyGSTi gate set tomography software to confirm their demonstration. |
News
Researchers Reveal What Happens to Your Brain When You Don’t Get Enough Sleep
What if poor sleep was doing more than just making you tired? Researchers have discovered that disrupted sleep in older adults interferes with the brain’s ability to clean out waste, leading to memory problems [...]
How to prevent chronic inflammation from zombie-like cells that accumulate with age
In humans and other multicellular organisms, cells multiply. This defining feature allows embryos to grow into adulthood, and enables the healing of the many bumps, bruises and scrapes along the way. Certain factors can [...]
Breakthrough for long Covid patients who lost sense of smell
A breakthrough nasal surgery has restored the sense of smell for a dozen long Covid patients. Experts at University College London Hospitals NHS Foundation Trust successfully employed a technique typically used for correcting blocked nasal passages, [...]
Scientists Invent Plastic That Can Dissolve In Seawater In Just A Few Hours
Plastic waste and pollution in the sea have been among the most serious environmental problems for decades, causing immense damage to marine life and ecosystems. However, a breakthrough discovery may offer a game-changing solution. [...]
Muscles from the 3D printer
Swiss researchers have developed a method for printing artificial muscles out of silicone. In the future, these could be used on both humans and robots. Swiss researchers have succeeded in printing artificial muscles out [...]
Beneficial genetic changes observed in regular blood donors
Researchers at the Francis Crick Institute have identified genetic changes in blood stem cells from frequent blood donors that support the production of new, non-cancerous cells. Understanding the differences in the mutations that accumulate [...]
Shocking Amounts of Microplastics in the Brain – It Could Be Increasing Our Risk of Dementia
The brain has higher concentrations of plastic particles compared to other organs, with increased levels found in dementia patients. In a comprehensive commentary published in Brain Medicine, researchers highlight alarming new evidence of microplastic accumulation [...]
Baffling Scientists for Centuries: New Study Unravels Mystery of Static Electricity
ISTA physicists demonstrate that contact electrification depends on the contact history of materials. For centuries, static electricity has intrigued and perplexed scientists. Now, researchers from the Waitukaitis group at the Institute of Science and [...]
Tumor “Stickiness” – Scientists Develop Potential New Way To Predict Cancer’s Spread
UC San Diego researchers have developed a device that predicts breast cancer aggressiveness by measuring tumor cell adhesion. Weakly adherent cells indicate a higher risk of metastasis, especially in early-stage DCIS. This innovation could [...]
Scientists Just Watched Atoms Move for the First Time Using AI
Scientists have developed a groundbreaking AI-driven technique that reveals the hidden movements of nanoparticles, essential in materials science, pharmaceuticals, and electronics. By integrating artificial intelligence with electron microscopy, researchers can now visualize atomic-level changes that were [...]
Scientists Sound Alarm: “Safe” Antibiotic Has Led to an Almost Untreatable Superbug
A recent study reveals that an antibiotic used for liver disease patients may increase their risk of contracting a dangerous superbug. An international team of researchers has discovered that rifaximin, a commonly prescribed antibiotic [...]
Scientists Discover Natural Compound That Stops Cancer Progression
A discovery led by OHSU was made possible by years of study conducted by University of Portland undergraduates. Scientists have discovered a natural compound that can halt a key process involved in the progression [...]
Scientists Just Discovered an RNA That Repairs DNA Damage – And It’s a Game-Changer
Our DNA is constantly under threat — from cell division errors to external factors like sunlight and smoking. Fortunately, cells have intricate repair mechanisms to counteract this damage. Scientists have uncovered a surprising role played by [...]
What Scientists Just Discovered About COVID-19’s Hidden Death Toll
COVID-19 didn’t just claim lives directly—it reshaped mortality patterns worldwide. A major international study found that life expectancy plummeted across most of the 24 analyzed countries, with additional deaths from cardiovascular disease, substance abuse, and mental [...]
Self-Propelled Nanoparticles Improve Immunotherapy for Non-Invasive Bladder Cancer
A study led by Pohang University of Science and Technology (POSTECH) and the Institute for Bioengineering of Catalonia (IBEC) in South Korea details the creation of urea-powered nanomotors that enhance immunotherapy for bladder cancer. The nanomotors [...]
Scientists Develop New System That Produces Drinking Water From Thin Air
UT Austin researchers have developed a biodegradable, biomass-based hydrogel that efficiently extracts drinkable water from the air, offering a scalable, sustainable solution for water access in off-grid communities, emergency relief, and agriculture. Discarded food [...]
