Toggle light / dark theme

Ultrafast plasmon-enhanced magnetic bit switching at the nanoscale

Researchers from Max Born Institute have demonstrated a successful way to control and manipulate nanoscale magnetic bits—the building blocks of digital data—using an ultrafast laser pulse and plasmonic gold nanostructures. The findings were published in Nano Letters.

All-optical, helicity-independent magnetization switching (AO-HIS) is one of the most interesting and promising mechanisms for this endeavor, where the magnetization state can be reversed between two directions with a single femtosecond laser pulse, serving as “0s” and “1s” without any or complex wiring. This opens up exciting possibilities for creating memory devices that are not only faster and more robust but also consume far less power.

Ultrafast light-driven control of magnetization on the nanometer-length scale is key to achieving competitive bit sizes in next-generation data storage technology. However, it is currently not well understood to what extent basic physics processes such as at the nanoscale and the propagation of magnetic domain walls limit the minimum achievable bit size.

All-optical switching on a nanometer scale

Ultrafast light-driven control of magnetization on the nanometer length scale is key to achieve competitive bit sizes in next generation data storage technology. Researchers at Max Born Institute in Berlin and of the large scale facility Elettra in Trieste, Italy, have successfully demonstrated the ultrafast emergence of all-optical switching by generating a nanometer scale grating by interference of two pulses in the extreme ultraviolet spectral range.

The physics of optically driven magnetization dynamics on the femtosecond time scale is of great interest for two main reasons: first, for a deeper understanding of the fundamental mechanisms of nonequilibrium, ultrafast spin dynamics and, second, for the potential application in the next generation of information technology with a vision to satisfy the need for both faster and more energy efficient data storage devices.

All– (AOS) is one of the most interesting and promising mechanisms for this endeavor, where the magnetization state can be reversed between two directions with a single femtosecond laser pulse, serving as “0s” and “1s.” While the understanding of the temporal control of AOS has progressed rapidly, knowledge on ultrafast transport phenomena on the nanoscale, important for the realization of all-optical magnetic reversal in technological applications, has remained limited due to the wavelength limitations of optical radiation. An elegant way to of overcoming these restrictions is to reduce the wavelengths to the extreme ultraviolet (XUV) spectral range in transient grating experiments. This technique is based on the interference of two XUV beams leading to a nanoscale excitation pattern and has been pioneered at the EIS-Timer beamline of the free-electron laser (FEL) FERMI in Trieste, Italy.

Quantum computing prepwork made faster with graph-based data grouping algorithm

Quantum computers promise to speed calculations dramatically in some key areas such as computational chemistry and high-speed networking. But they’re so different from today’s computers that scientists need to figure out the best ways to feed them information to take full advantage. The data must be packed in new ways, customized for quantum treatment.

High-pressure electron tunneling spectroscopy reveals nature of superconductivity in hydrogen-rich compounds

Scientists have achieved a major milestone in the quest to understand high-temperature superconductivity in hydrogen-rich materials. Using electron tunneling spectroscopy under high pressure, the international research team led by the Max Planck Institute for Chemistry has measured the superconducting gap of H3S—the material that set the high-pressure superconductivity record in 2015 and serves as the parent compound for subsequent high-temperature superconducting hydrides.

The findings, published this week in Nature, provide the first direct microscopic evidence of in hydrogen-rich materials and an important step toward its scientific understanding.

Superconductors are materials that can carry electrical current without resistance, making them invaluable for technologies such as energy transmission and storage, magnetic levitation, and quantum computing.

Tightening the math behind a key quantum process

An exact expression for a key process needed in many quantum technologies has been derived by a RIKEN mathematical physicist and a collaborator. This could help to guide advances in quantum technologies.

Many emerging such as and quantum communication rely on .

Entanglement is the mysterious phenomenon whereby two or more particles become so closely interconnected that, no matter how great the distance between them, they exhibit quantum correlations that far exceed the mutual relations achievable in .

Video game-inspired algorithm rapidly detects high-energy particle collisions for future fusion reactors

An innovative algorithm for detecting collisions of high-speed particles within nuclear fusion reactors has been developed, inspired by technologies used to determine whether bullets hit targets in video games. This advancement enables rapid predictions of collisions, significantly enhancing the stability and design efficiency of future fusion reactors.

Professor Eisung Yoon and his research team in the Department of Nuclear Engineering at UNIST announced that they have successfully developed a collision detection algorithm capable of quickly identifying collision points of high-speed particles within virtual devices. The research is published in the journal Computer Physics Communications.

When applied to the Virtual KSTAR (V-KSTAR), this algorithm demonstrated a detection speed up to 15 times faster than previous methods. The V-KSTAR is a digital twin that replicates the Korean Superconducting Tokamak Advanced Research (KSTAR) fusion experiment in a three-dimensional virtual environment.

From Laws to Algorithms: Reimagining the Mathematics of Reality

The juridical metaphor in physics has ancient roots. Anaximander, in the 6th century BCE, was perhaps the first to invoke the concept of cosmic justice, speaking of natural entities paying “penalty and retribution to each other for their injustice according to the assessment of Time” (Kirk et al., 2010, p. 118). This anthropomorphizing tendency persisted through history, finding its formal expression in Newton’s Principia Mathematica, where he articulated his famous “laws” of motion. Newton, deeply influenced by his theological views, conceived of these laws as divine edicts — mathematical expressions of God’s will imposed upon a compliant universe (Cohen & Smith, 2002, p. 47).

This legal metaphor has served science admirably for centuries, providing a framework for conceptualizing the universe’s apparent obedience to mathematical principles. Yet it carries implicit assumptions worth examining. Laws suggest a lawgiver, hinting at external agency. They imply prescription rather than description — a subtle distinction with profound philosophical implications. As physicist Paul Davies (2010) observes, “The very notion of physical law is a theological one in the first place, a fact that makes many scientists squirm” (p. 74).

Enter the computational metaphor — a framework more resonant with our digital age. The universe, in this conceptualization, executes algorithms rather than obeying laws. Space, time, energy, and matter constitute the data structure upon which these algorithms operate. This shift is more than semantic; it reflects a fundamental reconceptualization of physical reality that aligns remarkably well with emerging theories in theoretical physics and information science.

Chirality Switching On Demand

A device made of multilayer graphene exhibits topologically protected edge currents whose direction can be switched using an electric field.

Topological phases of matter have captivated physicists for several decades, promising exotic phenomena and new paradigms for electronic devices [1]. So-called Chern insulators—systems exhibiting quantized Hall conductance without an external magnetic field—are particularly enticing. These materials support dissipationless, one-way electron transport along their edges, which could enable robust low-power electronics or even form the backbone of future topological quantum-computing architectures [2]. Yet, the defining feature of a Chern insulator—its chirality, which determines the direction of the edge-state current—is set by material symmetry and is therefore notoriously rigid and difficult to manipulate dynamically [3–5].