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Tiny optical modulator could enable giant future quantum computers

Researchers have made a major advance in quantum computing with a new device that is nearly 100 times smaller than the diameter of a human hair.

Published in the journal Nature Communications, the breakthrough optical phase modulators could help unlock much larger quantum computers by enabling efficient control of lasers required to operate thousands or even millions of qubits—the basic units of quantum information.

Critically, the team of scientists have developed these devices using scalable manufacturing, avoiding complex, custom builds in favor of those used to make the same technology behind processors already found in computers, phones, vehicles, home appliances—virtually everything powered by electricity (even toasters).

New materials could boost the energy efficiency of microelectronics

MIT researchers have developed a new fabrication method that could enable the production of more energy efficient electronics by stacking multiple functional components on top of one existing circuit.

In traditional circuits, logic devices that perform computation, like transistors, and memory devices that store data are built as separate components, forcing data to travel back and forth between them, which wastes energy.

This new electronics integration platform allows scientists to fabricate transistors and memory devices in one compact stack on a semiconductor chip. This eliminates much of that wasted energy while boosting the speed of computation.

New iron telluride thin film achieves superconductivity for quantum computer chips

If quantum computing is going to become an every-day reality, we need better superconducting thin films, the hardware that enables storage and processing of quantum information. Too often, these thin films have impurities or other defects that make them useless for real quantum computer chips.

Now, Yuki Sato and colleagues at the RIKEN Center for Emergent Matter Science (CEMS) in Japan have discovered a way to make a superconducting thin film from iron telluride, which is surprising because it is not normally superconducting.

The fabrication process reduces distortion in the crystal structure, making it superconducting at very low temperatures, and thus suitable for use in quantum chips. This study was published in Nature Communications.

Theoretical results could lead to faster, more secure quantum technology

University of Iowa researchers have discovered a method to “purify” photons, an advance that could make optical quantum technologies more efficient and more secure.

The work is published in the journal Optica Quantum.

The researchers investigated two nagging challenges to creating a steady stream of single photons, the gold standard method for realizing photonic quantum computers and secure communication networks. One obstacle is called laser scatter, which occurs when a laser beam is directed at an atom, causing it to emit a photon, which is a single unit of light. While effective, the technique can yield extra, redundant photons, which hampers the optical circuit’s efficiency, much like a wayward current in an electrical circuit.

Medications change our gut microbiome in predictable ways

The bacteria in our poop are a reasonable representation of what’s living in our digestive system. To understand how different drugs can impact the gut microbiome, the team cultured microbial communities from nine donor fecal samples and systematically tested them with 707 different clinically relevant drugs.

The researchers examined changes in the growth of different bacterial species, the community composition, and the metabolome – the mix of small molecules called metabolites that microbes produce and consume. They found that 141 drugs altered the microbiome of the samples and even short-term treatments created enduring changes, entirely wiping out some microbial species. The primary force behind how the community responds to drug inhibition was competition over nutrients.

“The winners and losers among our gut bacteria can often be predicted by understanding how sensitive they are to the medications and how they compete for food,” said the first author on the paper. “In other words, drugs don’t just kill bacteria; they also reshuffle the ‘buffet’ in our gut, and that reshuffling shapes which bacteria win.”

Despite the complexity of the bacterial communities, the researchers were able to create data-driven computer models that accurately predicted how they would respond to a particular drug. They factored in the sensitivity of different bacterial species to that drug and the competitive landscape – essentially, who was competing with whom for which nutrients.

Their work provides a framework for predicting how a person’s microbial community might change with a given drug, and could help scientists find ways to prevent these changes or more easily restore a healthy gut microbiome in the future.


Our gut microbiome is made up of trillions of bacteria and other microbes living in our intestines. These help our bodies break down food, assist our immune system, send chemical signals to our brain, and potentially serve many other functions that researchers are still working to understand. When the microbiome is out of balance – with not enough helpful bacteria or the wrong combination of microbes – it can affect our whole body.

New nanomagnet production process improves efficiency and cuts costs

Researchers at HZDR have partnered with the Norwegian University of Science and Technology in Trondheim, and the Institute of Nuclear Physics in the Polish Academy of Sciences to develop a method that facilitates the manufacture of particularly efficient magnetic nanomaterials in a relatively simple process based on inexpensive raw materials.

Using a highly focused ion beam, they imprint magnetic nanostrips consisting of tiny, vertically aligned nanomagnets onto the materials. As the researchers have reported in the journal Advanced Functional Materials, this geometry makes the material highly sensitive to external magnetic fields and current pulses.

Nanomagnets play a key role in modern information technologies. They facilitate fast data storage, precise magnetic sensors, novel developments in spintronics, and, in the future, quantum computing. The foundations of all these applications are functional materials with particular magnetic structures that can be customized on the nanoscale and precisely controlled.

From light to logic: Ultrafast quantum switching in 2D materials

Scientists from the Indian Institute of Technology Bombay have found a way to use light to control and read tiny quantum states inside atom-thin materials. The simple technique could pave the way for computers that are dramatically faster and consume far less power than today’s electronics.

The materials studied are just one atom thick—far thinner than a human hair—and are known as two-dimensional (2D) semiconductors. Inside these materials, electrons can sit in one of two distinct quantum states, called valleys. These valleys, named K and K′, can be thought of as two different “locations” that an electron can choose between. Because there are two options, researchers have long imagined using them like the 0 and 1 of digital computing, but on a quantum level. This idea is the foundation of a rapidly growing research field called valleytronics.

However, being able to reliably control which valley electrons occupy—and to switch between them quickly and on demand—has been a major challenge. “Previous methods required complicated experimental setups with carefully tuned circularly polarized lasers and often multiple laser pulses, and they only worked under specific conditions,” said Prof. Gopal Dixit.

Surprising nanoscopic heat traps found in diamonds

Diamond is famous in material science for being the best natural heat conductor on Earth—but new research reveals that, at the atomic scale, it can briefly trap heat in unexpected ways. The findings could influence how scientists design diamond-based quantum technologies, including ultra-precise sensors and future quantum computers.

In a study published in Physical Review Letters, researchers from the University of Warwick and collaborators showed that when certain molecular-scale defects in diamond are excited with light, they create tiny, short-lived “hot spots” that momentarily distort the surrounding crystal. These distortions last only a few trillionths of a second but are long enough to affect the behavior of quantum-relevant defects.

“Finding a hot ground state for a molecular-scale defect in diamond was extremely surprising for us,” explained Professor James Lloyd-Hughes, Department of Physics, University of Warwick. “Diamond is the best thermal conductor, so one would expect energy transport to prevent any such effect. However, at the nanoscale, some phonons—packets of vibrational energy—hang around near the defect, creating a miniature hot environment that pushes on the defect itself.”

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