Lifeboat Foundation

By strategically straining materials that are as thin as a single layer of atoms, University of Rochester scientists have developed a new form of computing memory that is at once fast, dense, and low-power. The researchers outline their new hybrid resistive switches in a study published in Nature Electronics.

Developed in the lab of Stephen M. Wu, an assistant professor of electrical and computer engineering and of physics, the approach marries the best qualities of two existing forms of resistive switches used for memory: memristors and phase-change materials. Both forms have been explored for their advantages over today’s most prevalent forms of memory, including dynamic random access memory (DRAM) and flash memory, but they have their drawbacks.

Wu says that memristors, which apply voltage to a thin filament between two electrodes, tend to suffer from a relative lack of reliability compared to other forms of memory. Meanwhile, phase-change materials, which involve selectively melting a material into either an amorphous state or a crystalline state, require too much power.

Optical wireless may no longer have any obstacles. A study by Politecnico di Milano, conducted together with Scuola Superiore Sant’Anna in Pisa, the University of Glasgow and Stanford University, and published in Nature Photonics, has made it possible to create photonic chips that mathematically calculate the optimal shape of light to best pass through any environment, even one that is unknown or changing over time.

The problem is well known: light is sensitive to any form of obstacle, even very small ones. Think, for example, of how we see objects when looking through a frosted window or simply when our glasses get foggy. The effect is quite similar on a beam of light carrying data streams in optical wireless systems: the information, while still present, is completely distorted and extremely difficult to retrieve.

The devices developed in this research are small silicon chips that serve as smart transceivers: working in pairs, they can automatically and independently ‘calculate’ what shape a beam of light needs to be in order to pass through a generic environment with maximum efficiency. And that’s not all: they can also generate multiple overlapping beams, each with its own shape, and direct them without them interfering with each other; in this way, the transmission capacity is significantly increased, just as required by next-generation wireless systems.

“I think when you build a company from the ground up, and you’ve experienced real adversity, and you really experienced nearly going out of business several times, that feeling stays with you,” Huang said.

The fear of his chip empire tanking, Huang admitted, is a feeling he grapples with every morning when he wakes up.

“I don’t wake up proud and confident. I wake up worried and concerned,” Huang said as the audience laughed politely in response. “It just depends on which side of the bed you get out on.”

A speech prosthetic developed by a collaborative team of Duke neuroscientists, neurosurgeons, and engineers can translate a person’s brain signals into what they’re trying to say.

Appearing Nov. 6 in the journal Nature Communications, the new technology might one day help people unable to talk due to neurological disorders regain the ability to communicate through a brain-computer interface.

“There are many patients who suffer from debilitating motor disorders, like ALS (amyotrophic lateral sclerosis) or locked-in syndrome, that can impair their ability to speak,” said Gregory Cogan, Ph.D., a professor of neurology at Duke University’s School of Medicine and one of the lead researchers involved in the project. “But the current tools available to allow them to communicate are generally very slow and cumbersome.”

Quantum technologies are currently maturing at a breath-taking pace. These technologies exploit principles of quantum mechanics in suitably engineered systems, with bright prospects such as boosting computational efficiencies or communication security well beyond what is possible with devices based on today’s ‘classical’ technologies.

As with classical devices, however, to realize their full potential, quantum devices must be networked. In principle, this can be done using the fiber-optic networks employed for classical telecommunications. But practical implementation requires that the information encoded in quantum systems can be reliably stored at the frequencies used in telecom networks—a capability that has not yet been fully demonstrated.

Writing in Nature Communications, the group of Prof. Xiao-Song Ma at Nanjing University reports record-long quantum storage at telecom wavelengths on a platform that can be deployed in extended networks, paving the way for practical large-scale quantum networks.

When galaxies collide, their supermassive black holes enter into a gravitational dance, gradually orbiting each other ever closer until eventually merging. We know they merge because we see the gravitational beasts that result, and we have detected the gravitational waves they emit as they inspiral. But the details of their final consummation remain a mystery. Now a new paper published on the pre-print server arXiv suggests part of that mystery can be solved with a bit of dark matter.

Just as the famous three-body problem has no general analytical solution for Newtonian gravity, the two-body problem has no general solution in general relativity. So, we have to resort to computer simulations to model how black holes orbit each other and eventually merge.

For binary black holes that are relatively widely separated, our simulations work really well, but when black holes are close to each other things get complicated. Einstein’s equations are very nonlinear, and modeling the dynamics of strongly interacting black holes is difficult.

Quantum computing, the cutting-edge technology that promises unprecedented computational power, has taken a significant leap forward with the unveiling of a groundbreaking quantum chip by Amazon Web Services.

“It’s a custom-designed chip that’s totally fabricated in house by our AWS quantum team,” said Peter Desantis, senior vice president of AWS utility computing products, during a keynote address in Las Vegas at AWS’s re: Invent conference for the global cloud computing community.

DeSantis said the state-of-the-art chip represents a major milestone in the quest for error-corrected quantum computers. “We’ve been able to suppress errors by 100x by using a passive error correction approach,” he said.

A fundamental trade-off between the resolution of a clock and its accuracy could have important implications for quantum computers, which must measure short timescales accurately.

By Alex Wilkins

Few studies have investigated the structural properties of organic mixed ionic-electronic conductors in relation to the transient device characteristics. Here, Kim et al. show that backbone-dependent molecular orientation affects ion injection directionality, which determines ion mobility and transient response.