Researchers have long faced a significant hurdle in the development of practical quantum devices: the requirement for ultra-cold environments to maintain
Category: computing – Page 25
Engineers develop a magnetic transistor for more energy-efficient electronics
Transistors, the building blocks of modern electronics, are typically made of silicon. Because it’s a semiconductor, this material can control the flow of electricity in a circuit. But silicon has fundamental physical limits that restrict how compact and energy-efficient a transistor can be.
MIT researchers have now replaced silicon with a magnetic semiconductor, creating a magnetic transistor that could enable smaller, faster, and more energy-efficient circuits. The material’s magnetism strongly influences its electronic behavior, leading to more efficient control of the flow of electricity.
The team used a novel magnetic material and an optimization process that reduces the material’s defects, which boosts the transistor’s performance.
Ultrafast magnetization switching: Moving boundary challenges previous all-optical switching models
The field of ultrafast magnetism explores how flashes of light can manipulate a material’s magnetization in trillionths of a second. In the process called all-optical switching (AOS), a single laser pulse of several femtoseconds (≈10-15 seconds) duration flips tiny magnetic regions without the need for an externally applied magnetic field.
Enabling such an ultrafast control over magnetization, orders of magnitude faster than what can be achieved using a conventional magnet-based read/write head as in a magnetic hard drive, AOS is a promising candidate for novel spintronics devices that use magnetic spins with their associated magnetic moments as information carriers. Such devices typically consist of a stack of nanometer-thin materials, with the actual magnetic material being one of them.
Until now, the switching process was thought to happen uniformly in the magnetic material wherever the laser pulse deposits a sufficient amount of energy. In a study recently published in Nature Communications, researchers from the Max Born Institute together with collaborators from Berlin and Nancy revealed that this is not the case. Instead, there is an ultrafast propagation of a magnetization boundary into the depth of the material.
Self-locked microcomb on a chip tames Raman scattering to achieve broad spectrum and stable output
A research team has successfully developed a self-locked Raman-electro-optic (REO) microcomb on a single lithium niobate chip. By synergistically harnessing the electro-optic (EO), Kerr, and Raman effects within one microresonator, the microcomb has a spectral width exceeding 300 nm and a repetition rate of 26.03 GHz, without the need for external electronic feedback.
The research was published in the Nature Communications. The team was led by Prof. Dong Chunhua from the University of Science and Technology of China (USTC), in collaboration with Prof. Bo Fang’s group from Nankai University.
Optical frequency combs, light sources composed of equally spaced frequency lines, are essential tools in modern optical communications, precision measurement, and fundamental physics research. While traditional optical-frequency combs are typically based on bulky mode-locked lasers, recent advances in integrated photonics have enabled chip-scale Kerr and EO combs.
Computer Has One Instruction, Many Transistors
There’s always some debate around what style of architecture is best for certain computing applications, with some on the RISC side citing performance per watt and some on the CISC side citing performance per line of code. But when looking at instruction sets it’s actually possible to eliminate every instruction except one and still have a working, Turing-complete computer. This instruction is called subleq or “subtract and branch if less-than or equal to zero ”. [Michael] has built a computer that does this out of discrete components from scratch.
We’ll save a lot of the details of the computer science for [Michael] or others to explain, but at its core this is a computer running with a 1 kHz clock with around 700 transistors total. Since the goal of a single-instruction computer like this is simplicity, the tradeoff is that many more instructions need to be executed for equivalent operations. For this computer it takes six clock cycles to execute one instruction, for a total of about 170 instructions per second. [Michael] also created an assembler for this computer, so with an LCD screen connected and mapped to memory he can write and execute a simple hello world program just like any other computer.
[Michael] does note that since he was building this from Logisim directly he doesn’t have a circuit schematic, but due to some intermittent wiring issues might have something in the future if he decides to make PCBs for this instead of using wire on a cardboard substrate. There’s plenty of other information on his GitHub page though. It’s a unique project that gets to the core of what’s truly needed for a working computer. There are a few programming languages out there that are built on a similar idea.
MIT engineers develop a magnetic transistor for more energy-efficient electronics
Transistors, the building blocks of modern electronics, are typically made of silicon. Because it’s a semiconductor, this material can control the flow of electricity in a circuit. But silicon has fundamental physical limits that restrict how compact and energy-efficient a transistor can be.
MIT researchers have now replaced silicon with a magnetic semiconductor, creating a magnetic transistor that could enable smaller, faster, and more energy-efficient circuits. The material’s magnetism strongly influences its electronic behavior, leading to more efficient control of the flow of electricity.
The team used a novel magnetic material and an optimization process that reduces the material’s defects, which boosts the transistor’s performance.
Breakthrough: Quantum Entanglement Achieved Between The Hearts of Two Atoms
Quantum entanglement – once dismissed by Albert Einstein as “spooky action at a distance” – has long captured the public imagination and puzzled even seasoned scientists.
But for today’s quantum practitioners, the reality is rather more mundane: entanglement is a kind of connection between particles that is the quintessential feature of quantum computers.
Though these devices are still in their infancy, entanglement is what will allow them to do things classical computers cannot, such as better simulating natural quantum systems like molecules, pharmaceuticals, or catalysts.
Innovative transistor design offering advantages for controlling and reading quantum chips
The smaller electronic components become, the more complex their manufacture becomes. This has been a major problem for the chip industry for years. At TU Wien, researchers have now succeeded for the first time in manufacturing a silicon-germanium (SiGe) transistor using an alternative approach that will not only enable smaller dimensions in the future, but will also be faster, require less energy and function at extremely low temperatures, which is important for quantum chips.
The key trick lies in the oxide layer that insulates the semiconductor: it is doped and produces a long-range effect that extends into the semiconductor. The technology was developed by TU Wien (Vienna), JKU Linz and Bergakademie Freiberg. The results have now been published in the journal IEEE Electron Device Letters and selected as Editor’s Pick on the cover of the August issue.
Analog computing platform uses synthetic frequency domain to boost scalability
Analog computers, computing systems that represent data as continuous physical quantities, such as voltage, frequency or vibrations, can be significantly more energy-efficient than digital computers, which represent data as binary states (i.e., 0s and 1s). However, upscaling analog computing platforms is often difficult, as their underlying components can behave differently in larger systems.
Researchers at Virginia Tech, Oak Ridge National Laboratory and the University of Texas at Dallas have developed a new synthetic domain approach, a technique to encode information at different frequencies in a single device that could enable upscaling analog computers without the need to add more physical components.
Their proposed approach, outlined in a paper published in Nature Electronics, was used to develop a compact and highly efficient analog computing platform based on lithium niobate integrated nonlinear phononics.
