The breakthrough will allow scientists to research long sought-after high energy neutrinos.
This, combined with the esoteric rules of quantum mechanics, means that the spins are constantly in different positions at once. If you look at just a few particles, it’s hard to tell whether you have a quantum liquid or, if you do, what properties it has.
Quantum spin liquids were first theorized in 1973 by a physicist named Philip W. Anderson, and physicists have been trying to get their hands on this matter ever since. “Many different experiments…tried to create and observe this type of state. But this has actually turned out to be very challenging,” says Mikhail Lukin, a physicist at Harvard University and one of the paper authors.
The researchers at Harvard had a new tool in their arsenal: what they call a “programmable quantum simulator.” Essentially, it’s a machine that allows them to play with individual atoms. Using specifically focused laser beams, researchers can shuffle atoms around a two-dimensional grid like magnets on a whiteboard.
Let me back up a moment. I recently concurred with megapundit Steven Pinker that over the last two centuries we have achieved material, moral and intellectual progress, which should give us hope that we can achieve still more. I expected, and have gotten, pushback. Pessimists argue that our progress will prove to be ephemeral; that we will inevitably succumb to our own nastiness and stupidity and destroy ourselves.
Maybe, maybe not. Just for the sake of argument, let’s say that within the next century or two we solve our biggest problems, including tyranny, injustice, poverty, pandemics, climate change and war. Let’s say we create a world in which we can do pretty much anything we choose. Many will pursue pleasure, finding ever more exciting ways to enjoy themselves. Others may seek spiritual enlightenment or devote themselves to artistic expression.
No matter what our descendants choose to do, some will surely keep investigating the universe and everything in it, including us. How long can the quest for knowledge continue? Not long, I argued 25 years ago this month in The End of Science, which contends that particle physics, cosmology, neuroscience and other fields are bumping into fundamental limits. I still think I’m right, but I could be wrong. Below I describe the views of three physicists—Freeman Dyson, Roger Penrose and David Deutsch—who hold that knowledge seeking can continue for a long, long time, and possibly forever, even in the face of the heat death of the universe.
Quantum computer and many other quantum technologies rely on the generation of quantum-entangled pairs of electrons. However, the systems developed so far typically produce a noisy and random flow of entangled electrons, which hinders synchronized operations on the entangled particles. Now, researchers from Aalto University in Finland propose a way to produce a regular flow of spin-entangled electrons.
Their solution is based on a dynamically driven Cooper pair splitter. In a Cooper pair splitter, two quantum dots near a superconductor are used to generate and separate a pair of entangled electrons known as a Cooper pair. When the Cooper pair splitter is driven with a static voltage, the result is a random and noisy process.
A theoretical analysis by the Aalto team showed that driving the system dynamically with external gate voltages makes it possible to control the timing of the splitting process. As a result, exactly one pair of entangled electrons can be extracted during each splitting cycle, leading to a completely noiseless and regular flow of spin-entangled electrons.
Because leviathan black holes would never fit in a lab, Jeff Steinhauer and his research team created a mini one right here on Earth.
When something rips physics apart, you cross over into the quantum realm, a place inhabited by black holes, wormholes and other things that have been the stars of multiple sci-fi movies. What lives in the quantum realm either hasn’t been proven to exist (yet) or behaves strangely if it does exist.
Black holes often venture into that realm. With these collapsed stars — at least most of them are — being impossible to fly a spacecraft into (unless you never want to see it again), one physicist decided that the best way to get up close to them was under a literal microscope. Jeff Steinhauer wanted to know whether black holes radiate particles like the late Stephen Hawking theorized they would. Because one of these leviathans would never fit in a lab, he and his research team created one right here on Earth.
A 2D nanomaterial consisting of organic molecules linked to metal atoms in a specific atomic-scale geometry shows non-trivial electronic and magnetic properties due to strong interactions between its electrons.
A new study, published today, shows the emergence of magnetism in a 2D organic material due to strong electron-electron interactions; these interactions are the direct consequence of the material’s unique, star-like atomic-scale structure.
This is the first observation of local magnetic moments emerging from interactions between electrons in an atomically thin 2D organic material.
As particles travel through the Universe, there’s a speed limit to how fast they’re allowed to go. No, not the speed of light: below it.
Are you in the market for a loophole in the laws that forbid perpetual motion? Knowing you’ve got yourself an authentic time crystal takes more than a keen eye for high-quality gems.
In a new study, an international team of researchers used Google’s Sycamore quantum computing hardware to double-check their theoretical vision of a time crystal, confirming it ticks all of the right boxes for an emerging form of technology we’re still getting our head around.
Similar to conventional crystals made of endlessly repeating units of atoms, a time crystal is an infinitely repeating change in a system, one that remarkably doesn’t require energy to enter or leave.
An international team led by EPFL scientists, has unveiledthat has only been observed in engineered atomic thin layers. The phenomenon can be reproduced by the native defects of lab grown large crystals, making future investigation of Kondo systems and quantum electronic devices more accessible.
The properties of materials that are technologically interesting often originate from defects on their atomic structure. For example, changing the optical properties of rubies with chrome inclusions has helped develop lasers, while nitrogen-vacancy in diamonds are paving the way for applications such as quantum magnetometers. Even in the metallurgical industry, atomic-scale defects like dislocation enhances the strength of forged steel.
Another manifestation of atomic-scale defects is the Kondo effect, which affects a metal’s conduction properties by scattering and slowing the electrons and changing the flow of electrical current through it. This Kondo effect was first observed in metals with very few magnetic defects, e.g. gold with few parts per million of iron inclusions. When the diluted magnetic atoms align all the electrons spin around them, this slows the electrical current motion inside the material, equally along every direction.
Research has long strived to develop computers to work as energy efficiently as our brains. A study, led by researchers at the University of Gothenburg, has succeeded for the first time in combining a memory function with a calculation function in the same component. The discovery opens the way for more efficient technologies, everything from mobile phones to self-driving cars.
In recent years, computers have been able to tackle advanced cognitive tasks, like language and image recognition or displaying superhuman chess skills, thanks in large part to artificial intelligence (AI). At the same time, the human brain is still unmatched in its ability to perform tasks effectively and energy efficiently.
“Finding new ways of performing calculations that resemble the brain’s energy-efficient processes has been a major goal of research for decades. Cognitive tasks, like image and voice recognition, require significant computer power, and mobile applications, in particular, like mobile phones, drones and satellites, require energy efficient solutions,” says Johan Åkerman, professor of applied spintronics at the University of Gothenburg.
