Lifeboat Foundation

Since the invention of the laser in 1960, nonlinear optics has aimed to broaden light’s spectral range and create new frequency components. Among the various techniques, supercontinuum (SC) generation stands out for its ability to produce light across a wide portion of the visible and infrared spectrum.

However, traditional SC sources rely on weak third-order optical nonlinearity, requiring long interaction lengths for broad spectral output. In contrast, second-order optical nonlinearity offers far greater efficiency and lower power requirements, though phase mismatching in bulk crystals has historically limited its spectral coverage and overall efficiency.

In a study published in Light: Science & Applications, a collaborative research team from Aalto University, Tampere University, and Peking University, led by Professor Zhipei Sun, has demonstrated a revolutionary method for generating octave-spanning coherent light at the deep-subwavelength scale (100 nm). Their innovative approach employs phase-matching-free second-order nonlinear optical frequency down-conversion in ultrathin gallium selenide (GaSe) and niobium oxide diiodide (NbOI₂) crystals.

A team of physicists led by The City College of New York’s Lia Krusin-Elbaum has developed a novel technique that uses hydrogen cations (H⁺) to manipulate relativistic electronic bandstructures in a magnetic Weyl semimetal—a topological material where electrons mimic massless particles called Weyl fermions. These particles are distinguished by their chirality or “handedness” linked to their spin and momentum.

In the magnetic material MnSb₂Te₄, researchers unveiled a fascinating ability to “tune” and enhance the chirality of electronic transport by introducing hydrogen ions, reshaping on-demand the energy landscapes—called Weyl nodes—within the material. This finding could open a breadth of new quantum device platforms for harnessing emergent topological states for novel chiral nano-spintronics and fault-tolerant quantum computing. Entitled “Transport chirality generated by a tunable tilt of Weyl nodes in a van der Waals topological magnet,” the study appears in the journal Nature Communications.

The tuning of Weyl nodes with H⁺ heals the system’s (Mn-Te) bond disorder and lowers the internode scattering. In this process—which The City College team tests in the Krusin Lab using angularly-resolved electrical transport—electrical charges move differently when the in-plane magnetic field is rotated clockwise or counterclockwise, generating desirable low-dissipation currents. The reshaped Weyl states feature a doubled Curie temperature and a strong angular transport chirality synchronous with a rare field-antisymmetric longitudinal resistance—a low-field tunable ‘chiral switch’ that is rooted in the interplay of topological Berry curvature, chiral anomaly and a hydrogen-mediated form of Weyl nodes.

The discovery of an isotope, rutherfordium-252, whose ground state forestalls fission for just 60 nanoseconds, could help theorists understand the cosmic synthesis of superheavy elements.

Researchers have measured graphene’s plasmon spectrum using a novel electron-based spectroscopy technique.

Artificial neural networks (ANNs) have brought about many stunning tools in the past decade, including the Nobel-Prize-winning AlphaFold model for protein-structure prediction [1]. However, this success comes with an ever-increasing economic and environmental cost: Processing the vast amounts of data for training such models on machine-learning tasks requires staggering amounts of energy [2]. As their name suggests, ANNs are computational algorithms that take inspiration from their biological counterparts. Despite some similarity between real and artificial neural networks, biological ones operate with an energy budget many orders of magnitude lower than ANNs. Their secret? Information is relayed among neurons via short electrical pulses, so-called spikes. The fact that information processing occurs through sparse patterns of electrical pulses leads to remarkable energy efficiency.

Researchers have successfully simulated the non-Hermitian skin effect in a two-dimensional quantum system, a first in the field.

This groundbreaking work, which uses ultracold fermions, reveals potential for a deeper understanding of quantum systems interacting with their environment, paving the way for future discoveries in quantum physics and information.

Groundbreaking Quantum Simulation Achievement.

Primordial black holes could reshape our understanding of dark matter. Researchers suggest these elusive cosmic phenomena might be hiding within hollow asteroids or planetoids, detectable through straightforward, cost-effective methods.

Are Primordial Black Holes real? These elusive objects are thought to have formed during the chaotic early moments of the Universe, shortly after the Big Bang

The Big Bang is the leading cosmological model explaining how the universe as we know it began approximately 13.8 billion years ago.

Researchers have discovered that neurotransmitters like dopamine.

Dopamine is a crucial neurotransmitter involved in many important functions in the brain, particularly those related to pleasure, reward, motivation, and motor control. It plays a central role in the brain’s reward system, where it helps reinforce rewarding behaviors by increasing pleasure and satisfaction, making it critical for habit formation and addictive behaviors. Dopamine is also vital for regulating movement, and deficiencies in dopamine production are linked to neurological disorders such as Parkinson’s disease. Additionally, dopamine influences various other functions, including mood regulation, learning, and attention, making it a key focus in studies of both mental health and neurodegenerative diseases.

Microsoft’s January 2025 update addresses 161 vulnerabilities, including 3 zero-days and 5 critical flaws.