How can a computer chip the size of a human hair enhance the future of quantum computing? This is what a recent study published in Nature Communications ho | Technology
Category: computing – Page 10
Caltech Team Sets Record with 6,100-Qubit Array
Quantum computers will need large numbers of qubits to tackle challenging problems in physics, chemistry, and beyond. Unlike classical bits, qubits can exist in two states at once—a phenomenon called superposition. This quirk of quantum physics gives quantum computers the potential to perform certain complex calculations better than their classical counterparts, but it also means the qubits are fragile. To compensate, researchers are building quantum computers with extra, redundant qubits to correct any errors. That is why robust quantum computers will require hundreds of thousands of qubits.
Now, in a step toward this vision, Caltech physicists have created the largest qubit array ever assembled: 6,100 neutral-atom qubits trapped in a grid by lasers. Previous arrays of this kind contained only hundreds of qubits.
This milestone comes amid a rapidly growing race to scale up quantum computers. There are several approaches in development, including those based on superconducting circuits, trapped ions, and neutral atoms, as used in the new study.
The neutral-atom platform shows promise for scaling up quantum computers.
How Bose-Einstein condensates replicate Shapiro steps
The microscopic processes taking place in superconductors are difficult to observe directly. Researchers at the RPTU University of Kaiserslautern-Landau have therefore implemented a quantum simulation of the Josephson effect: They separated two Bose-Einstein condensates (BECs) by means of an extremely thin optical barrier.
The characteristic Shapiro steps were observed in the atomic system. The research was published in the journal Science.
Two superconductors separated by a wafer-thin insulating layer—that’s how simple a Josephson junction looks. But despite its simple structure, it harbors a quantum mechanical effect that is now one of the most important tools of modern technology: Josephson contacts form the heart of many quantum computers and enable high-precision measurements—such as the measurement of very weak magnetic fields.
Pinpointing the glow of a single atom to advance quantum emitter engineering
Researchers have discovered how to design and place single-photon sources at the atomic scale inside ultrathin 2D materials, lighting the path for future quantum innovations.
Like perfectly controlled light switches, quantum emitters can turn on the flow of single particles of light, called photons, one at a time. These tiny switches—the “bits” of many quantum technologies—are created by atomic-scale defects in materials.
Their ability to produce light with such precision makes them essential for the future of quantum technologies, including quantum computing, secure communication and ultraprecise sensing. But finding and controlling these atomic light switches has been a major scientific challenge—until now.
Kingston launches Dual Portable SSD with up to 2TB storage
Supports high-speed transfer between USB-A and USB-C devices
Scientists Uncover How Tiny “Nanopores” Learn Like the Brain
Scientists found that nanopores’ electrical charges control how ions flow and when pores temporarily shut down. The discovery could allow engineers to design nanopores that “learn” like synapses for next-generation computing.
Pore-forming proteins appear across many forms of life. In humans, they help protect the body by supporting immune defenses. In bacteria, they often function as toxins that create openings in cell membranes. These natural pores regulate the movement of ions and molecules, and their precise control over molecular transport has made them valuable in biotechnology, including DNA sequencing and molecular sensing.
Unpredictable Behavior in Ion Flow.
Epitaxial multilayer MoS2 wafers promise high-performance transistors
Two-dimensional (2D) semiconductors, such as molybdenum disulfide (MoS2), enable unprecedented opportunities to solve the bottleneck of transistor scaling and to build novel logic circuits with faster speeds, lower power consumption, flexibility and transparency, benefiting from their ultra-thin thickness, dangling-bond-free flat surface and excellent gate controllability.
Tremendous efforts have been devoted to exploring the scaled-up potentials of monolayer MoS2, including both wafer-scale synthesis of high-quality materials and large-area devices. For instance, four-inch wafer-scale monolayer MoS2 with large domain sizes (up to ~300 μm) and record-high electronic quality (average field-effect mobility of ~80 cm2·V-1 ·s-1) has already been demonstrated via van der Waals epitaxial growth.
In terms of a further improvement of the electronic quality of the large-scale monolayer MoS2, structural imperfections should be eliminated as much as possible; however, there is not much space left for monolayer MoS2 after ten years of synthesis optimizations in this field. Another key direction is to switch to multilayer MoS2, e.g., bilayers and trilayers, since they have intrinsically higher electronic quality than monolayers and thus are conducive to higher-performance devices and logic circuits. However, due to the fundamental limitation of thermodynamics, it is still a great challenge to realize wafer-scale multilayer MoS2 with high-quality and large-scale uniformity.
Real-life ‘quantum molycircuits’ using exotic nanotubes
Molybdenum disulfide MoS2 is a groundbreaking material for electronics applications. As a two-dimensional layer similar to graphene, it is an excellent semiconductor, and can even become intrinsically superconducting under the right conditions. It’s not particularly surprising that science fiction authors have already been speculating about molycircs, fictional computer circuits built from MoS2, for years—and that physicists and engineers are directing huge research efforts at this material.
Researchers at the University of Regensburg, have many years of expertise with diverse quantum materials—in particular also with carbon nanotubes, tube-like macromolecules made from carbon atoms alone.
“It was an obvious next step to now focus on MoS2 and its fascinating properties,” said Dr. Andreas K. Hüttel, head of the research group Nanotube Electronics and Nanomechanics in Regensburg. In cooperation with Prof. Dr. Maja Remškar, Jožef Stefan Institut Ljubljana, a specialist in the crystalline growth of molybdenum disulfide nanomaterials, his research group started working on quantum devices based on MoS2 nanotubes.
New method realize ohmic contacts in n-type MoS₂ transistors at cryogenic temperatures
Semiconducting transition metal dichalcogenides (TMDs) are a class of layered materials exhibiting unique optoelectronic properties that could be leveraged to develop transistors, sensors and other nanoelectronics. Despite their advantages, creating robust ohmic contacts that connect a metal electrode in transistors to semiconducting TMDs at cryogenic temperatures has proved challenging.
This has so far limited the use of these materials for either studying fundamental physics or developing nanoelectronics that operate at low temperatures.
In a paper in Nature Electronics, researchers at the Liaoning Academy of Materials, Shanxi University and other institutes introduced a new technique for realizing ohmic contacts to the TMD molybdenum disulfide (MoS2) at cryogenic temperatures, and found that electron mobility in those transistors can be surprisingly high.