Quantum mechanically entangled groups of eight and ten ultracold atoms provide a critical demonstration for optical-lattice-based quantum processing.
Graphene nanoribbons have outstanding properties that can be precisely controlled. Researchers from Empa and ETH Zurich, in collaboration with partners from Peking University, the University of Warwick and the Max Planck Institute for Polymer Research, have succeeded in attaching electrodes to individual atomically precise nanoribbons, paving the way for precise characterization of the fascinating ribbons and their possible use in quantum technology.
Quantum technology is promising, but also perplexing. In the coming decades, it is expected to provide us with various technological breakthroughs: smaller and more precise sensors, highly secure communication networks, and powerful computers that can help develop new drugs and materials, control financial markets, and predict the weather much faster than current computing technology ever could.
To achieve this, we need so-called quantum materials: substances that exhibit pronounced quantum physical effects. One such material is graphene. This two-dimensional structural form of carbon has unusual physical properties, such as extraordinarily high tensile strength, thermal and electrical conductivity—as well as certain quantum effects. Restricting the already two-dimensional material even further, for instance, by giving it a ribbon-like shape, gives rise to a range of controllable quantum effects.
“There’s no road map,” said Michael Sipser, a veteran complexity theorist at the Massachusetts Institute of Technology who spent years grappling with the problem in the 1980s. “It’s like you’re going into the wilderness.”
It seems that proving that computational problems are hard to solve is itself a hard task. But why is it so hard? And just how hard is it? Carmosino and other researchers in the subfield of meta-complexity reformulate questions like this as computational problems, propelling the field forward by turning the lens of complexity theory back on itself.
Computer simulations confirm that the African Superplume causes the unusual deformations and rift-parallel seismic anisotropy detected below the East African Rift System.
Continental rifting involves a combination of stretching and fracturing that penetrates deep within the Earth, explains geophysicist D. Sarah Stamps. This process pertains to the elongation of the lithosphere, Earth’s rigid outer layer. As it becomes more taut, the lithosphere’s upper sections undergo brittle changes, leading to rock fractures and earthquakes.
Stamps, who studies these processes by using computer modeling and GPS.
Trinity’s quantum physicists in collaboration with IBM Dublin have successfully simulated super diffusion in a system of interacting quantum particles on a quantum computer.
This is the first step in doing highly challenging quantum transport calculations on quantum hardware and, as the hardware improves over time, such work promises to shed new light in condensed matter physics and materials science.
Continue reading “Research team simulates super diffusion on a quantum computer” »
Not many pure-play quantum computing start-ups have dared to go public. So far, the financial markets have tended to treat the newcomers unsparingly. One exception is IonQ, who along with D-Wave and Rigetti, reported quarterly earnings last week. Buoyed by hitting key technical and financial goals, IonQ’s stock is up ~400% (year-to-date) and CEO Peter Chapman is taking an aggressive stance in the frothy quantum computing landscape where error correction – not qubit count – has increasingly taken center stage as the key challenge.
This is all occurring at a time when a wide variety of different qubit types are vying for dominance. IBM, Google, and Rigetti are betting on superconducting-based qubits. IonQ and Quantinuuum use trapped ions. Atom Computing and QuEra use neutral atoms. PsiQuantum and Xanadu rely on photonics-based qubits. Microsoft is exploring topological qubits based on the rare Marjorana particle. And more are in the works.
It’s not that the race to scale up qubit-count has ended. IBM has a 433-plus qubit device (Osprey) now and is scheduled to introduce 1100-qubit device (Condor) late this year. Several other quantum computer companies have devices in the 50–100 qubit range. IonQ’s latest QPU, Forte, has 32 qubits. The challenge they all face is that current error rates remain so high that it’s impractical to reliably run most applications on the current crop of QPUs.
Published: August 8, 2023 8.29am EDT
Alexis souchet, university of southern california.
The big idea.
Researchers have found a way to control the interaction of light and quantum ‘spin’ in organic semiconductors, that works even at room temperature.
Spin is the term for the intrinsic angular momentum of electrons, which is referred to as up or down. Using the up/down spin states of electrons instead of the 0 and 1 in conventional computer logic could transform the way in which computers process information. And sensors based on quantum principles could vastly improve our abilities to measure and study the world around us.
An international team of researchers, led by the University of Cambridge, has found a way to use particles of light as a ‘switch’ that can connect and control the spin of electrons, making them behave like tiny magnets that could be used for quantum applications.
Research is underway around the world to find alternatives to our current electronic computing technology, as great, electron-based systems have limitations. A new way of transmitting information is emerging from the field of magnonics. Instead of electron exchange, the waves generated in magnetic media could be used for transmission, but magnonics-based computing has been (too) slow to date.
Scientists at the University of Vienna have now discovered a significant new method. When the intensity is increased, the spin waves become shorter and faster—another step towards magnon computing. The results are published in the journal Science Advances.
Magnonics is a relatively new field of research in magnetism in which spin waves play a central role. A local disturbance in the magnetic order of a magnet can propagate as waves through a material. These waves are called spin waves, and the associated quasiparticles are called magnons. They carry information in the form of angular momentum pulses. Because of this property, they can be used as low-power data carriers in smaller and more energy-efficient computers of the future.
The physics of cell communication: ISTA scientists successfully model cell dynamics.
Like us, cells communicate. Well, in their own special way. Using waves as their common language, cells tell one another where and when to move. They talk, they share information, and they work together – much like the interdisciplinary team of researchers from the Institute of Science and Technology Austria (ISTA) and the National University of Singapore (NUS). They conducted research on how cells communicate – and how that matters to future projects, e.g. application to wound healing.
Biology may evoke images of animals, plants, or even theoretical computer models. The last association might not immediately come to mind, yet it is crucial in biological research. Complex biological phenomena, even the minutest details, can be understood through precise calculations. ISTA Professor Edouard Hannezo utilizes these calculations to comprehend physical principles in biological systems. His team’s recent work provides new insights into how cells move and communicate within living tissue.
