Lifeboat Foundation

Researchers have created a quantum superposition state in a semiconductor nanostructure that might serve as a basis for quantum computing. The trick: two optical laser pulses that act as a single terahertz laser pulse.

A German-Chinese research team has successfully created a quantum bit in a semiconductor nanostructure. Using a special energy transition, the researchers created a superposition state in a quantum dot—a tiny area of the semiconductor—in which an electron hole simultaneously possessed two different energy levels. Such superposition states are fundamental for quantum computing.

However, excitation of the state would require a large-scale free-electron laser that can emit light in the terahertz range. Additionally, this wavelength is too long to focus the beam on the tiny quantum dot. The German-Chinese team has now achieved the excitation with two finely tuned short-wavelength optical laser pulses.

For decades, scientists have been probing the potential of two-dimensional materials to transform our world. 2D materials are only a single layer of atoms thick. Within them, subatomic particles like electrons can only move in two dimensions. This simple restriction can trigger unusual electron behavior, imbuing the materials with “exotic” properties like bizarre forms of magnetism, superconductivity and other collective behaviors among electrons—all of which could be useful in computing, communication, energy and other fields.

But researchers have generally assumed that these exotic 2D properties exist only in single-layer sheets, or short stacks. The so-called “bulk” versions of these materials—with their more complex 3D atomic structures—should behave differently.

Or so they thought.

The semiconductor industry warned that there won’t be enough engineers, computer scientists and technicians in the US to support a rapid expansion this decade, threatening efforts to boost the domestic chip economy.

A scalable system for controlling quantum bits demonstrates a very low error rate, which is essential for making practical devices.

A major obstacle to the development of practical quantum computers is the difficulty of scaling up—making a device with large numbers of quantum bits (qubits) that also gives accurate results in the presence of environmental noise. Now researchers report a significant improvement in the accuracy of a technology that is already known to be much easier to scale up than conventional techniques [1]. This alternative technology uses units of magnetic flux called flux quanta to control conventional superconducting qubits. The reduction in the error rate came from physically separating the control circuits from the qubits. With further refinement, the flux-quanta technology could provide a superior pathway to practical quantum computation.

Many current efforts to carry out quantum logic operations—the basic units of computation—use short microwave pulses to control the qubits. Currently, however, this technology is difficult to scale up beyond 1,000 qubits. But the presence of environmental noise requires error-correction methods that rely on large numbers of qubits, perhaps a million or more, for an effective error-correcting system that performs useful computations, according to some estimates.

As fish wriggle, they create a complex push–pull pattern in the water that propels them forward. Many studies have shown how the motion of a fish’s tail forms a vortex around its leading edge that provides thrust; however, it has been difficult to capture how the water flow around other parts of the fish interacts with this vortex to impact the overall propulsion. Jiacheng Guo at the University of Virginia and colleagues recently demonstrated how different fins create currents that can constructively interact to improve swimming efficiency [1].

Guo and colleagues studied how the flow around the lower back—or anal—fin interacts with the flow around the tail—or caudal—fin. First, they took a high-resolution video of a swimming rainbow trout and created a computational fluid dynamics model to accurately reproduce the fish’s motion and the water currents that it induced. Then they modified the anal fin in the model to see how this would change the pattern of water flow around the trout and affect the forward thrust.

The researchers found that the anal fin increases propulsion in two ways. It creates a vortex that stabilizes and strengthens the caudal-fin vortex, and it helps maintain a pressure difference across the fish’s body that reduces drag. Changes to the size or position of the anal fin decreased the swimming efficiency, demonstrating that the natural fish physiology is optimal.

A study shows it’s possible to use laser-based systems with optical transistors to transfer information far more quickly than possible today.

Neuromorphic computers do not calculate using zeros and ones. They instead use physical phenomena to detect patterns in large data streams at blazing fast speed and in an extremely energy-efficient manner.

In their project NIMFEIA, Katrin and Helmut Schultheiß along with their team from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) have now taken this technology a tremendous step forward. They also demonstrated that their approach can be seamlessly integrated into conventional chip manufacturing. Their findings have now been published in Nature Communications.

What the researchers have developed at the HZDR-Institute of Ion Beam Physics and Materials Research is referred to by many names. “Neuromorphic computing,” for example, is one term, as the processes resemble those that occur within the brain. “Unconventional computing” is another name, as the technology is so different from the data processing that we are accustomed to today, which uses the Boolean logic of zeros and ones.

With the launch of the Mac Pro and M2 Ultra chip at WWDC in June, all eyes are now on the next phase of Apple silicon and the highly anticipated M3 processor. And according to a new report, every Mac in Apple’s lineup will be getting in on the action.

In his latest Power On newsletter, Mark Gurman reports that an M3 Mac mini is “a sure thing,” as is a new MacBook Pro with M3 Pro and M3 Max processors. The Mac mini has previously gone years between updates, so it’s notable that Apple plans to refresh it so soon after the release of the M2 model.

Gurman previously reported that Apple is planning to launch the M3 chip alongside three new Macs: the 13-inch MacBook Air, the 13-inch MacBook Pro, and the 24-inch iMac. We can also expect to see an M3 version of the 15-inch Air, if not at the same time then within a few months of the announcement.

Halide perovskites are a family of materials that have attracted attention for their superior optoelectronic properties and potential applications in devices such as high-performance solar cells, light-emitting diodes, and lasers.

Caption :

A new MIT platform enables researchers to “grow” halide perovskite nanocrystals with precise control over the location and size of each individual crystal, integrating them into nanoscale light-emitting diodes. Pictured is a rendering of a nanocrystal array emitting light.