Lifeboat Foundation

Scientists develop an energy-efficient strategy to reversibly change ‘spin orientation’ or magnetization direction in magnetite at room temperature.

Over the last few decades, conventional electronics has been rapidly reaching its technical limits in computing and information technology, calling for innovative devices that go beyond the mere manipulation of electron current. In this regard, spintronics, the study of devices that exploit the “spin” of electrons to perform functions, is one of the hottest areas in applied physics. But, measuring, altering, and, in general, working with this fundamental quantum property is no mean feat.

Current spintronic devices — for example, magnetic tunnel junctions — suffer from limitations such as high-power consumption, low operating temperatures, and severe constraints in material selection. To this end, a team of scientists at Tokyo University of Science and the National Institute for Materials Science (NIMS), Japan, has published a study in ACS Nano, in which they present a surprisingly simple yet efficient strategy to manipulate the magnetization angle in magnetite (Fe₃O₄), a typical ferromagnetic material.

## GENERAL FUSION (VANCOUVER) • JUN 16, 2021.

# General Fusion to build its Fusion Demonstration Plant in the UK, at the UKAEA Culham Campus.

*Unlike conventional nuclear power, which involves fission or splitting atoms, the emerging fusion technology promises clean energy where the only emission would be helium, and importantly, no radioactive waste.*

Continue reading “General Fusion to build its Fusion Demonstration Plant in the UK, at the UKAEA Culham Campus” »

Fusion energy has the potential to supply safe, clean, and nearly limitless power. Although fusion reactions can occur for light nuclei weighting less than iron, most elements will not fuse unless they are in the interior of a star. To create burning plasmas in experimental fusion power reactors such as tokamaks and stellarators, scientists seek a fuel that is relatively easy to produce, store, and bring to fusion. The current best bet for fusion reactors is deuterium-tritium fuel. This fuel reaches fusion conditions at lower temperatures compared to other elements and releases more energy than other fusion reactions.

Deuterium and tritium are isotopes of hydrogen, the most abundant element in the universe. Whereas all isotopes of hydrogen have one proton, deuterium also has one neutron and tritium has two neutrons, so their ion masses are heavier than protium, the isotope of hydrogen with no neutrons. When deuterium and tritium fuse, they create a helium nucleus, which has two protons and two neutrons. The reaction releases an energetic neutron. Fusion power plants would convert energy released from fusion reactions into electricity to power our homes, businesses, and other needs.

Fortunately, deuterium is common. About 1 out of every 5000 hydrogen atoms in seawater is in the form of deuterium. This means our oceans contain many tons of deuterium. When fusion power becomes a reality, just one gallon of seawater could produce as much energy as 300 gallons of gasoline.

Learning the results sparked a moment of joyous celebration, Park says: high fives to everyone.

“This is some of the first experimental evidence of the formation of these collisionless shocks,” says plasma physicist Francisco Suzuki-Vidal of Imperial College London, who was not involved in the study. “This is something that has been really hard to reproduce in the laboratory.”

Continue reading “Giant lasers help re-create supernovas’ explosive, mysterious physics” »

Circa 2019

A quark–gluon plasma is produced in proton–gold, deuteron–gold and helium–gold collisions. Observing elliptic and triangular flow in this nearly inviscid fluid from these different initial geometries provides a unique benchmark for hydrodynamic models.

Circa 2019

Decay is relentless in the macroscopic world: broken objects do not fit themselves back together again. However, other laws are valid in the quantum world: new research shows that so-called quasiparticles can decay and reorganize themselves again and are thus become virtually immortal. These are good prospects for the development of durable data memories.

Research explains how aurora-creating particles are accelerated.

Biological systems are dynamical, constantly exchanging energy and matter with the environment in order to maintain the non-equilibrium state synonymous with living. Developments in observational techniques have allowed us to study biological dynamics on increasingly small scales. Such studies have revealed evidence of quantum mechanical effects, which cannot be accounted for by classical physics, in a range of biological processes. Quantum biology is the study of such processes, and here we provide an outline of the current state of the field, as well as insights into future directions.

Quantum mechanics is the fundamental theory that describes the properties of subatomic particles, atoms, molecules, molecular assemblies and possibly beyond. Quantum mechanics operates on the nanometre and sub-nanometre scales and is at the basis of fundamental life processes such as photosynthesis, respiration and vision. In quantum mechanics, all objects have wave-like properties, and when they interact, quantum coherence describes the correlations between the physical quantities describing such objects due to this wave-like nature.

In photosynthesis, respiration and vision, the models that have been developed in the past are fundamentally quantum mechanical. They describe energy transfer and electron transfer in a framework based on surface hopping. The dynamics described by these models are often ‘exponential’ and follow from the application of Fermi’s Golden Rule [1, 2]. As a consequence of averaging the rate of transfer over a large and quasi-continuous distribution of final states the calculated dynamics no longer display coherences and interference phenomena. In photosynthetic reaction centres and light-harvesting complexes, oscillatory phenomena were observed in numerous studies performed in the 1990s and were typically ascribed to the formation of vibrational or mixed electronic–vibrational wavepackets.

In 2013, François Englert and Peter Higgs won the Nobel Prize in Physics for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, which was confirmed through the discovery of the predicted fundamental particle by the A Toroidal LHC Apparatus (ATLAS) and the Compact Muon Solenoid (CMS) experiments at The European Organization for Nuclear Research (CERN)’s Large Hadron Collider in 2012. The Higgs mode or the Anderson-Higgs mechanism (named after another Nobel Laureate Philip W Anderson), has widespread influence in our current understanding of the physical law for mass ranging from particle physics—the elusive “God particle” Higgs boson discovered in 2012 to the more familiar and important phenomena of superconductors and magnets in condensed matter physics and quantum material research.

The Higgs mode, together with the Goldstone mode, is caused by the spontaneous breaking of continuous symmetries in the various quantum material systems. However, different from the Goldstone mode, which has been widely observed via neutron scattering and nuclear magnetic resonance spectroscopies in quantum magnets or superconductors, the observation of the Higgs mode in the material is much more challenging due to its usual overdamping, which is also the property in its particle physics cousin—the elusive Higgs boson. In order to weaken these damping, two paths have been suggested from the theoretical side, through quantum critical points and dimensional crossover from high dimensions to lower ones. For , people have achieved several remarkable results, whereas there are few successes in.

To fulfill this knowledge gap, from 2020, Mr Chengkang Zhou, then a first-year Ph.D. student, Dr. Zheng Yan and Dr. Zi Yang Meng from the Research Division for Physics and Astronomy of the University of Hong Kong (HKU), designed a dimensional crossover setting via coupled spin chains. They applied the quantum Monte Carlo (QMC) simulation to investigate the excitation spectra of the problem. Teaming up with Dr. Hanqing Wu from the Sun Yat-Sen University, Professor Kai Sun from the University of Michigan, and Professor Oleg A Starykh from the University of Utah, they observed three different kinds of collective excitation in the quasi-1D limit, including the Goldstone mode, the Higgs mode and the scalar mode. By combining numerical and analytic analyses, they successfully explained these excitations, and in particular, revealed the clear presence of the Higgs mode in the quasi-1D quantum magnetic systems.