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The fundamental principles of thermodynamics have long been a cornerstone of our understanding of the physical world, with the second law of thermodynamics standing as a testament to the inexorable march towards disorder and entropy that governs all closed systems. However, the realm of quantum physics has traditionally appeared to defy this notion, with mathematical formulations suggesting that entropy remains constant in these systems.

Recent research has shed new light on this seeming paradox, revealing that the apparent contradiction between quantum mechanics and thermodynamics can be reconciled through a nuanced understanding of entropy itself. By adopting a definition of entropy that is compatible with the principles of quantum physics, specifically the concept of Shannon entropy, scientists have demonstrated that even isolated quantum systems will indeed evolve towards greater disorder over time, their entropy increasing as the uncertainty of measurement outcomes grows.

This breakthrough insight has far-reaching implications for our comprehension of the interplay between quantum theory and thermodynamics, and is poised to play a pivotal role in the development of novel quantum technologies that rely on the manipulation of complex many-particle systems.

An experiment in Sweden has demonstrated control over a novel kind of magnetism, giving scientists a new way to explore a phenomenon with huge potential to improve electronics – from memory storage to energy efficiency.

Using a device that accelerates electrons to blinding speeds, a team led by researchers from the University of Nottingham showered an ultra-thin wafer of manganese telluride with X-rays of different polarizations, to reveal changes on a nanometer scale reflecting magnetic activity unlike anything seen before.

For a rather mundane chunk of iron to transform into something a little more magnetic, its constituent particles need to be arranged so that their unpartnered electrons align according to a property known as spin.

Quantum networks require quantum nodes that are built using quantum dots.


However, a new study impressively solves these challenges. The study authors successfully used 13,000 nuclear spins in a gallium arsenide (GaAs) quantum dot system to create a scalable quantum register.

Quantum networks require quantum nodes that are built using quantum dots — tiny particles, much smaller than a human hair, which can trap and control electrons, and store quantum information.

Quantum dots are valued for their ability to emit single photons because single-photon sources are key requirements for secure quantum communication and quantum computing applications.

Everyone has their favourite example of a trick that reliably gets a certain job done, even if they don’t really understand why. Back in the day, it might have been slapping the top of your television set when the picture went fuzzy. Today, it might be turning your computer off and on again.

Quantum mechanics — the most successful and important theory in modern physics — is like that. It works wonderfully, explaining things from lasers and chemistry to the Higgs boson and the stability of matter. But physicists don’t know why. Or at least, if some of us think we know why, most others don’t agree.

Graphene is an allotrope of carbon in the form of a single layer of atoms in a two-dimensional hexagonal lattice in which one atom forms each vertex. It is the basic structural element of other allotropes of carbon, including graphite, charcoal, carbon nanotubes, and fullerenes. In proportion to its thickness, it is about 100 times stronger than the strongest steel.

What do eyes, quantum collapse, and photon emission have in common?

While experimenting with a simple particle simulation, an unexpected phenomenon emerged that bridges multiple realms of physics and perception.

The simulation, designed to model particles moving in toroidal orbits while attracting each other, spontaneously developed a striking pattern: a perfectly centered emission of particles perpendicular to the toroid’s plane, resembling both an eye and a quantum emission event.

Spin Hall nano-oscillators (SHNOs) are nanoscale spintronic devices that convert direct current into high-frequency microwave signals through spin wave auto-oscillations. This is a type of nonlinear magnetization oscillations that are self-sustained without the need for a periodic external force.

Theoretical and simulation studies found that propagating spin-wave modes, in which spin waves move across materials instead of being confined to the auto-oscillation region, can promote the coupling between SHNOs.

This coupling may in turn be harnessed to adjust the timing of oscillations in these devices, which could be advantageous for the development of neuromorphic computing systems and other spintronic devices.

A groundbreaking discovery by researchers at the University of California, Los Angeles (UCLA) has challenged a long-standing rule in organic chemistry known as Bredt’s Rule. Established nearly a century ago, this rule stated that certain types of specific organic molecules could not be synthesized due to their instability. UCLA’s team’s findings open the door to new molecular structures that were previously deemed unattainable, potentially revolutionizing fields such as pharmaceutical research.

To grasp the significance of this breakthrough, it’s helpful to first understand some basics of organic chemistry. Organic chemistry primarily deals with molecules made of carbon, such as those found in living organisms. Among these, certain molecules known as olefins or alkenes feature double bonds between two carbon atoms. These double bonds create a specific geometry: the atoms and atom groups attached to them are generally in the same plane, making these structures fairly rigid.

In 1924, German chemist Julius Bredt formulated a rule regarding certain molecular structures called bridged bicyclic molecules. These molecules have a complex structure with multiple rings sharing common atoms, akin to two intertwined bracelet loops. Bredt’s Rule dictates that these molecules cannot have a double bond at a position known as the bridgehead, where the two rings meet. The rule is based on geometric reasons: a double bond at the bridgehead would create such significant structural strain that the molecule would become unstable or even impossible to synthesize.