Lifeboat Foundation

Physicists have observed a difference in the decay of particles containing the charm quark and its antiparticle, perhaps helping to explain why matter exists at all.

The most popular contender over the past few decades has been string theory, and the related concepts of superstring theory and M-theory, in which particles are considered as tiny units of one-dimensional string. However, a lesser-known theory has also gained traction; loop quantum gravity (LQG), which attempts to solve the quantum gravity problem by focusing on the very fabric of spacetime, rather than the particles themselves.

In “Quantum Space,” the popular-science writer Jim Baggott lays out the basic principles of LQG for science enthusiasts. The book looks at how loop quantum gravity has emerged by following the work of two of its leading proponents, Carlo Rovelli and Lee Smolin, and assesses where the theory is now, and where it might be going.

Although the concepts are — not surprisingly — mind-boggling, Baggott asks deep questions about the nature of the universe, what space is actually composed of, and the existence of time itself. (The book covers a lot of challenging material, however, and some prior reading may help readers find their way.)

When a particle is completely isolated from its environment, the laws of quantum physics start to play a crucial role. One important requirement to see quantum effects is to remove all thermal energy from the particle motion, i.e. to cool it as close as possible to absolute zero temperature. Researchers at the University of Vienna, the Austrian Academy of Sciences and the Massachusetts Institute of Technology (MIT) are now one step closer to reaching this goal by demonstrating a new method for cooling levitated nanoparticles. They now publish their results in the renowned journal Physical Review Letters.

Tightly focused laser beams can act as optical “tweezers” to trap and manipulate tiny objects, from glass particles to living cells. The development of this method has earned Arthur Ashkin the last year’s Nobel prize in physics. While most experiments thus far have been carried out in air or liquid, there is an increasing interest for using optical tweezers to trap objects in ultra-high vacuum: such isolated particles not only exhibit unprecedented sensing performance, but can also be used to study fundamental processes of nanoscopic heat engines, or quantum phenomena involving large masses.

A key element in these research efforts is to obtain full control over the particle motion, ideally in a regime where the laws of quantum physics dominate its behavior. Previous attempts to achieve this, have either modulated the optical tweezer itself, or immersed the particle into additional light fields between highly reflecting mirror configurations, i.e. optical cavities.

Continue reading “Quantum optical cooling of nanoparticles” »

An electron spin resonance spectrometer using an artificial atom (a superconducting flux qubit) is realized, featuring both high sensitivity (400 spins/√Hz) and high spatial resolution (0.05 pL).

Hiraku Toida

Continue reading “A single superconducting artificial atom senses solid-state spins” »

The ABRACADABRA experiment sounds like magic but it may help uncover an elusive, invisible particle.

by

• Jackson Ryan

Everything you see around you is made up of elementary particles called quarks and leptons, which can combine to form bigger particles such as protons or atoms.

But that doesn’t make them boring – these subatomic particles can also combine in exotic ways we’ve never spotted.

Now CERN’s LHCb collaboration has announced the discovery of a clutch of new particles dubbed “pentaquarks”. The results can help unveil many mysteries of the theory of quarks, a key part of the standard model of particle physics.

Continue reading “Physicists Discover a Mysterious New Class of Particles Containing Five Quarks” »

SciTech Europa explores some of the research taking place in the exciting field of spintronics, from spin-orbit coupling to practical spintronic devices.

If you throw a ball at a wall, it’s going to bounce back at you – that’s classical physics at work. But of course, the world of quantum physics is much spookier, so if you did the same with a particle, there’s a chance that it will suddenly appear on the other side. This is thanks to a phenomenon known as quantum tunneling, and now a team of physicists has measured just how long that process takes.

Scientists at CERN have today announced that they’re 99.99% sure that they’ve found a new sub-atomic particle, and that it is likely to be the elusive Higgs boson – often referred to as the “God Particle”. That’s all well and good, but what does it all mean? Let’s break it down…