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Category: computing – Page 274

Researchers in Germany and the U.S. have shown for the first time that terahertz (THz) light pulses can stabilize ferromagnetism in a crystal at temperatures more than three times its usual transition temperature. As the team reports in Nature, using pulses just hundreds of femtoseconds long (a millionth of a billionth of a second), a ferromagnetic state was induced at high temperature in the rare-earth titanate YTiO3 which persisted for many nanoseconds after the light exposure. Below the equilibrium transition temperature, the laser pulses still strengthened the existing magnetic state, increasing the magnetization up to its theoretical limit.

Using light to control magnetism in solids is a promising platform for future technologies. Today’s computers mainly rely on the flow of electrical charge to process information. Moreover, digital memory storage devices make use of magnetic bits that must be switched external magnetic fields. Both of these aspects limit the speed and energy efficiency of current computing systems. Using light instead to optically switch memory and computing devices could revolutionize processing speeds and efficiency.

YTiO3 is a transition metal oxide that only becomes ferromagnetic, with properties resembling those of a fridge magnet, below 27 K or −246°C. At these low temperatures, the spins of the electrons on the Ti atoms align in a particular direction. It is this collective ordering of the spins which gives the material as a whole a macroscopic magnetization and turns it ferromagnetic. In contrast, at temperatures above 27 K, the individual spins fluctuate randomly so that no ferromagnetism develops.

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We’re hearing this week from two very different parts of the string theory community that quantum supremacy (quantum computers doing better than classical computers) is the answer to the challenges the subject has faced.

New Scientist has an article Quantum computers could simulate a black hole in the next decade which tells us that “Understanding the interactions between quantum physics and gravity within a black hole is one of the thorniest problems in physics, but quantum computers could soon offer an answer.” The article is about this preprint from Juan Maldacena which discusses numerical simulations in a version of the BFSS matrix model, a 1996 proposal for a definition of M-theory that never worked out. Maldacena points to this recent Monte-Carlo calculation, which claims to get results consistent with expectations from duality with supergravity.

Maldacena’s proposal is basically for a variant of the wormhole publicity stunt: he argues that if you have a large enough quantum computer, you can do a better calculation than the recent Monte-Carlo. In principle you could look for quasi-normal modes in the data, and then you would have created not a wormhole but a black hole and be doing “quantum gravity in the laboratory”.

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Researchers have developed a new high-speed way to detect the location, size and category of multiple objects without acquiring images or requiring complex scene reconstruction. Because the new approach greatly decreases the computing power necessary for object detection, it could be useful for identifying hazards while driving.

“Our technique is based on a single-pixel detector, which enables efficient and robust multi– directly from a small number of 2D measurements,” said research team leader Liheng Bian from the Beijing Institute of Technology in China. “This type of image-free sensing technology is expected to solve the problems of heavy communication load, high computing overhead and low perception rate of existing visual perception systems.”

Today’s image-free perception methods can only achieve classification, single object recognition or tracking. To accomplish all three at once, the researchers developed a technique known as image-free single-pixel object detection (SPOD). In Optics Letters, they report that SPOD can achieve an object detection accuracy of just over 80%.

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Great, until the mention of “directed energy”…

Researchers at the University of Maryland (UMD) have demonstrated a continuously operating optical fiber made of thin air.

The most common optical fibers are strands of glass that tightly confine light over long distances. However, these fibers are not well-suited for guiding extremely high-power beams due to glass damage and scattering of laser energy out of the fiber. Additionally, the need for a physical support structure means that glass fiber must be laid down long in advance of light signal transmission or collection.

Howard Milchberg and his group in UMD’s Departments of Physics and Electrical & Computer Engineering and Institute for Research in Electronics & Applied Physics have demonstrated an optical guiding method that beats both limitations, using auxiliary ultrashort laser pulses to sculpt fiber optic waveguides in the air itself.

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When Apple’s M1 chip made its debut in November 2020, it not only shook up the Mac, it shook up the whole computer industry, outperforming chips from giants such as Intel (which Apple ditched) and AMD. Those companies have been doing their best to catch up and lo and behold, AMD now claims its latest laptop chip, the 7840U, is faster than Apple’s M2.

According to AMD, its new Ryzen 7 7840U shows improvement over the M2 that ranges from 5 percent in web browsing to 75 in the Passmark 10 benchmark tool. (We wonder why it doesn’t supply specific numbers or use a more common tool such as Geekbench or Cinebench.) Macworld’s sister site, PCWorld, states that the 7840U is meant to be used in lower-power laptops, which is likely why AMD compares its chip to the M2 that is in the MacBook Air and 13-inch MacBook Pro. Apple’s M2 Pro and M2 Max in the 14-and 16-inch MacBook Pro are significantly faster than the M2–and almost certainly faster than the 7840U–but those laptops and chips require much more power.

AMD.

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A solar-powered motorhome, shaped like a huge elongated teardrop, silently rolled into Madrid on Friday as part of a month-long journey from the Netherlands to southern Spain to highlight more sustainable modes of transport.

Engineering students at the Technical University of Eindhoven in the Netherlands created the blue and white vehicle, named Stella Vita – Latin for “star” and “life” – to inspire car makers and politicians to accelerate the transition toward green energy.

Expansive solar panels on the roof and on lateral wings that unfold when the vehicle stops allow the self-sustaining house on wheels, or SHOW, to travel up to 740 km (460 miles) on a sunny day, while the battery can also power a fridge, coffee maker and laptop in the two-person cabin.

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In the ceaseless pursuit of energy-efficient computing, new devices designed at UC Santa Barbara show promise for enhancements in information processing and data storage.

Researchers in the lab of Kaustav Banerjee, a professor of electrical and computer engineering, have published a new paper describing several of these devices, “Quantum-engineered devices based on 2D materials for next-generation information processing and storage,” in the journal Advanced Materials. Arnab Pal, who recently received his doctorate, is the lead author.

Each device is intended to address challenges associated with conventional computing in a new way. All four operate at very low voltages and are characterized as being low leakage, as opposed to the conventional metal-oxide semiconductor field-effect transistors (MOSFETs) found in smartphones that drain power even when turned off. But because they are based on processing steps similar to those used to make MOSFETs, the new devices could be produced at scale using existing industry-standard manufacturing processes for semiconductors.

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Technophobia is an extreme fear of technology. People with technophobia may fear the power of artificial intelligence, robots or computers.

Technophobia is more than resistance to learning new technology. Rather, people with the condition may obsess over technology. Or, they may go to great lengths to avoid incorporating technology into their lives.

Technophobia is not a clinical diagnosis in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Still, as technology has expanded rapidly in recent years, some clinicians treat technophobia like a specific phobia. Specific phobias are irrational fears of a particular situation, object, animal or interaction. The fear isn’t in proportion to the actual danger.

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UNSW Sydney researchers have developed a chip-scale method using OLEDs to image magnetic fields, potentially transforming smartphones into portable quantum sensors. The technique is more scalable and doesn’t require laser input, making the device smaller and mass-producible. The technology could be used in remote medical diagnostics and material defect identification.

Smartphones could one day become portable quantum sensors thanks to a new chip-scale approach that uses organic light-emitting diodes (OLEDs) to image magnetic fields.

Researchers from the ARC Centre of Excellence in Exciton Science at UNSW Sydney have demonstrated that OLEDs, a type of semiconductor material commonly found in flat-screen televisions, smartphone screens, and other digital displays, can be used to map magnetic fields using magnetic resonance.

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