Lifeboat Foundation

MIT researchers have found a new mechanism by which the superconductor iron selenide transitions into a superconducting state. Unlike other iron-based superconductors, iron selenide’s transition involves a collective shift in atoms’ orbital energy, not atomic spins. This breakthrough opens up new possibilities for discovering unconventional superconductors.

Under certain conditions — usually exceedingly cold ones — some materials shift their structure to unlock new, superconducting behavior. This structural shift is known as a “nematic transition,” and physicists suspect that it offers a new way to drive materials into a superconducting state where electrons can flow entirely friction-free.

But what exactly drives this transition in the first place? The answer could help scientists improve existing superconductors and discover new ones.

You’re familiar with the states of matter we encounter daily – such as solid, liquid, and gas – but in more exotic and extreme conditions, new states can appear, and scientists from the US and China just found one.

They’re calling it the chiral bose-liquid state, and as with every new arrangement of particles we discover, it can tell us more about the fabric and the mechanisms of the Universe around us – and in particular, at the super-small quantum scale.

States of matter describe how particles can interact with one another, giving rise to structures and various ways of behaving. Lock atoms in place, and you have a solid. Allow them to flow, you have a liquid or gas. Force charged partnerships apart, you have a plasma.

Most of us don’t think of atoms as having their own unique vibrations, but they do. In fact, it’s a feature so fundamental to nature’s building blocks that a team of University of Washington researchers recently observed and used this phenomenon in their research study. By studying the light atoms emitted when stimulated by a laser, they were able to detect vibrations sometimes referred to as atomic “breathing.”

The result is a breakthrough that may one day allow us to build better tools for many kinds of quantum technologies.

Led by Mo Li, a professor of photonics and nano devices in both the UW Department of Electrical and Computer Engineering and the UW Physics Department, the researchers set out to build a better quantum emitter, or QE, one that could be incorporated into optical circuits.

Water and carbon make a quantum couple: the flow of water on a carbon surface is governed by an unusual phenomenon dubbed quantum friction. A new work published in Nature Nanotechnology experimentally demonstrates this phenomenon—which was predicted in a previous theoretical study—at the interface between liquid water and graphene, a single layer of carbon atoms. Advanced ultrafast techniques were used to perform this study. These results could lead to applications in water purification and desalination processes and maybe even to liquid-based computers.

For the last 20 years, scientists have been puzzled by how water behaves near carbon surfaces. It may flow much faster than expected from conventional flow theories or form strange arrangements such as square ice. Now, an international team of researchers from the Max Plank Institute for Polymer Research of Mainz (Germany), the Catalan Institute of Nanoscience and Nanotechnology (ICN2, Spain), and the University of Manchester (England), reports in the study published in Nature Nanotechnology on June 22, 2023, that water can interact directly with the carbon’s electrons—a quantum phenomenon that is very unusual in fluid dynamics.

A liquid, such as water, is made up of small molecules that randomly move and constantly collide with each other. A solid, in contrast, is made of neatly arranged atoms that bathe in a cloud of electrons. The solid and the liquid worlds are assumed to interact only through collisions of the liquid molecules with the solid’s atoms—the liquid molecules do not “see” the solid’s electrons. Nevertheless, just over a year ago, a paradigm-shifting theoretical study proposed that at the water-carbon interface, the liquid’s molecules and the solid’s electrons push and pull on each other, slowing down the liquid flow: this new effect was called quantum friction. However, the theoretical proposal lacked experimental verification.

Quantum computing, just like traditional computing, needs a way to store the information it uses and processes. On the computer you’re using right now, information, whether it be photos of your dog, a reminder about a friend’s birthday, or the words you’re typing into browser’s address bar, must be stored somewhere. Quantum computing, being a new field, is still working out where and how to store quantum information.

In a paper published in the journal Nature Physics, Mohammad Mirhosseini, assistant professor of electrical engineering and applied physics, shows a new method his lab has developed for efficiently translating electrical quantum states into sound and vice versa. This type of translation may allow for storing quantum information prepared by future quantum computers, which are likely to made from electrical circuits.

This method makes use of what are known as phonons, the sound equivalent of a light particle called a photon. (Remember that in quantum mechanics, all waves are particles and vice versa). The experiment investigates phonons for storing quantum information because it’s relatively easy to build small devices that can store these mechanical waves.

After a search of neutron stars finds preliminary evidence for hypothetical dark matter particles called axions, astrophysicists are devising new ways to spot them.

The discovery of the quantum Hall effects in the 1980s revealed the existence of novel states of matter called “Laughlin states,” in honor of the American Nobel prize winner who successfully characterized them theoretically. These exotic states specifically emerge in 2D materials, at very low temperature and in the presence of an extremely strong magnetic field.

In a Laughlin state, electrons form a peculiar liquid, where each electron dances around its congeners while avoiding them as much as possible. Exciting such a quantum liquid generates collective states that physicists associate with fictitious particles, whose properties drastically differ from electrons: these “anyons” carry a fractional charge (a fraction of the elementary charge) and they surprisingly defy the standard classification of particles in terms of bosons or fermions.

For many years, physicists have explored the possibility of realizing Laughlin states in other types of systems than those offered by solid-state materials, in view of further analyzing their peculiar properties. However, the required ingredients (the 2D nature of the system, the intense magnetic field, the strong correlations among the particles) has proved extremely challenging.

A new kind of resonator has the ability to transmit quantum information using single photons from a silicon device tipped with a few dozen erbium atoms.

The quantum internet just got one step closer to reality thanks to a new breakthrough that allows the encoded quantum information to be transmitted over distance.

The quantum internet offers the promise of perfect information security on a quantum mechanical level in the transmission of information using qubits, which will decompose into random information if anyone were to try and intercept it.

Researchers at Microsoft say they have created elusive quasiparticles called Majorana zero modes – but scientists outside the company are sceptical.

By Karmela Padavic-Callaghan