Lifeboat Foundation

Europe is pushing to create a network infrastructure based on quantum physics.

In May 2023, Dr. Benjamin Lanyon at the University of Innsbruck in Austria took an important step toward creating a new kind of internet: he transferred information along an optical fiber 50 kilometers long using the principles of quantum physics.

Information in quantum physics differs from the units of data—binary digits—stored and processed by computers that form the core of the current World Wide Web. The quantum physics realm covers the properties and interactions of molecules, atoms and even smaller particles such as electrons and photons.

Absorption spectroscopy is an analytical chemistry tool that can determine if a particular substance is present in a sample by measuring the intensity of the light absorbed as a function of wavelength. Measuring the absorbance of an atom or molecule can provide important information about electronic structure, quantum state, sample concentration, phase changes or composition changes, among other variables, including interaction with other molecules and possible technological applications.

Molecules with a high probability of simultaneously absorbing two photons of low-energy light have a wide array of applications: in molecular probes for high-resolution microscopy, as a substrate for data storage in dense three-dimensional structures, or as vectors in medicinal treatments, for example.

Studying the phenomenon by means of direct experimentation is difficult, however, and computer simulation usually complements spectroscopic characterization. Simulation also provides a microscopic view that is hard to obtain in experiments. The problem is that simulations involving relatively large molecules require several days of processing by supercomputers or months by conventional computers.

In a recent publication in EPJ Quantum Technology, Le Bin Ho from Tohoku University’s Frontier Institute for Interdisciplinary Sciences has developed a technique called time-dependent stochastic parameter shift in the realm of quantum computing and quantum machine learning. This breakthrough method revolutionizes the estimation of gradients or derivatives of functions, a crucial step in many computational tasks.

Typically, computing derivatives requires dissecting the function and calculating the rate of change over a small interval. But even classical computers cannot keep dividing indefinitely. In contrast, quantum computers can accomplish this task without having to discrete the function. This feature is achievable because quantum computers operate in a realm known as “quantum space,” characterized by periodicity, and no need for endless subdivisions.

One way to illustrate this concept is by comparing the sizes of two elementary schools on a map. To do this, one might print out maps of the schools and then cut them into smaller pieces. After cutting, these pieces can be arranged into a line, with their total length compared (see Figure 1a). However, the pieces may not form a perfect rectangle, leading to inaccuracies. An infinite subdivision would be required to minimize these errors, an impractical solution, even for classical computers.

Whether improperly closing a door or shanking a kick in soccer, our brains tell us when we’ve made a mistake because these sounds differ from what we expect to hear. While it’s long been established that our neurons spot these errors, it has been unclear whether there are brain cells that have only one job—to signal when a sound is unexpected or “off.”

A team of New York University neuroscientists has now identified a class of neurons—what it calls “prediction-error neurons”—that are not responsive to sounds in general, but only respond when sounds violate expectations, thereby sending a message that a mistake has been made.

“Brains are remarkable at detecting what’s happening in the world, but they are even better at telling you whether what happened was expected or not,” explains David Schneider, an assistant professor in NYU’s Center for Neural Science and the senior author of the study, which appears in JNeurosci. “We found that there are specific neurons in the brain that don’t tell you what happened, but instead tell you what went wrong.”

Researchers have developed a method that can reveal the location of errors in quantum computers, making them up to 10 times easier to correct. This will significantly accelerate progress towards large-scale quantum computers capable of tackling the world’s most challenging computational problems, the researchers said.

Led by Princeton University’s Jeff Thompson, the team demonstrated a way to identify when errors occur in quantum computers more easily than ever before. This is a new direction for research into quantum computing hardware, which more often seeks to simply lower the probability of an error occurring in the first place.

A paper detailing the new approach was published in Nature on Oct. 11. Thompson’s collaborators include Shruti Puri at Yale University and Guido Pupillo at Strasbourg University.

Scientists testing a new method of sequencing single cells have unexpectedly changed our understanding of the rules of genetics.

The genome of a protist has revealed a seemingly unique divergence in the DNA

DNA, or deoxyribonucleic acid, is a molecule composed of two long strands of nucleotides that coil around each other to form a double helix. It is the hereditary material in humans and almost all other organisms that carries genetic instructions for development, functioning, growth, and reproduction. Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA).

Here is how the brain adapts to diverse styles.

Scientists at Yale and the Southwest Research Institute (SRI) say they’ve hit the jackpot with some valuable new information about the story of gold.

It’s a story that begins with violent collisions of large objects in space, continues in a half-melted region of Earth’s mantle, and ends with precious metals finding an unlikely resting spot much closer to the planet’s surface than scientists would have predicted.

Jun Korenaga, a professor of Earth and planetary sciences in Yale’s Faculty of Arts and Sciences, and Simone Marchi, a researcher at SRI in Boulder, Colorado, provide details in a study in the journal Proceedings of the National Academy of Sciences.

Scientists studied genetic samples from more than 7,000 people and linked three genetic variants, inherited from Neanderthals, to increased pain sensitivity.