by Chris Smith

April 05, 2016

from BGR Website

 

It might sound boring to most people, but the fact that scientists have finally been able to prove there's a new state of matter is very exciting, as it could have applications for the future of computing.

In short, scientists from the University of Cambridge and the Oak Ridge National Laboratory in Tennessee were able to prove that a state of matter theorized some 40 years ago does exist.

The new state of matter is known as "quantum spin liquid" and is made of electrons that break into smaller quasiparticles, as Science Alert explains.

The electron is the fundamental element of matter, which can't be divided into smaller blocks.

However, this new experiment proves that electrons can fractionalize though they're not really breaking into additional components.

"This is a new quantum state of matter, which has been predicted but hasn't been seen before," Cambridge researcher Johannes Knolle said.

The researchers were able to prove that quantum spin liquid exists and they observed the Majorana fermions that result from electron fractionalization.

These fermions are exciting because they could be used to build quantum computers in the future, the kind of machines that will significantly outperform existing computers.

The quantum spin liquid state makes electrons act weirdly, but until these experiments, researchers did not know how this theoretical matter state would look or behave.

In a typical magnetic material, all electrons behave similarly.

Cooled to low enough temperature, the electrons order themselves so that all the north magnetic poles point in the same direction. But with a material containing a quantum spin liquid, the electrons don't align anymore under the same conditions.

Scientists were able to prove that electron fractionalization and Majorana fermions exist by using neuron scattering techniques and observing the effects in alpha-ruthenium chloride, a material similar to graphene - the full study (Proximate Kitaev Quantum Spin Liquid Behavior in a Honeycomb Magnet) explaining this new state of matter.

Meanwhile, the following video explains how electrons can "break" into smaller particles, and how the technology could be used to build quantum computers.

Scientists Have Just Discovered a...

New State of Matter
by Fiona MacDonald
05 April 2016

from ScienceAlert Website

 

Researchers have just discovered evidence of a mysterious new state of matter in a real material.

The state is known as 'quantum spin liquid' and it causes electrons - one of the fundamental, indivisible building blocks of matter - to break down into smaller quasiparticles.

Scientists had first predicted the existence of this state of matter in certain magnetic materials 40 years ago, but despite multiple hints of its existence, they've never been able to detect evidence of it in nature.

So it's pretty exciting that they've now caught a glimpse of quantum spin liquid, and the bizarre fermions that accompany it, in a two-dimensional, graphene-like material.

"This is a new quantum state of matter, which has been predicted but hasn't been seen before," said one of the researchers, Johannes Knolle, from the University of Cambridge in the UK.

They were able to spot evidence of quantum spin liquid in the material by observing one of its most intriguing properties - electron fractionalization - and the resulting Majorana fermions, which occur when electrons in a quantum spin state split apart.

These Majorana fermions are exciting because they could be used as building blocks of quantum computers:

To be clear, the electrons aren't actually splitting down into smaller physical particles - which of course would be an even bigger deal (that would mean brand new particles!). 

What's happening instead is the new state of matter is breaking electrons down into quasiparticles. These aren't actually real particles, but are concepts used by physicists to explain and calculate the strange behavior of particles.

And the quantum spin liquid state is definitely making electrons act weirdly - in a typical magnetic material, electrons behave like tiny bar magnets.

So when the material is cooled to a low enough temperature, these magnet-like electrons order themselves over long ranges, so that all the north magnetic poles point in the same direction.

But in a material containing a quantum spin liquid state, even if a magnetic material is cooled to absolute zero, the electrons don't align, but instead form an entangled soup caused by quantum fluctuations.

"Until recently, we didn't even know what the experimental fingerprints of a quantum spin liquid would look like," said one of the researchers, Dmitry Kovrizhin.

 

"One thing we've done in previous work is to ask, if I were performing experiments on a possible quantum spin liquid, what would I observe?"

To figure out what was going on, the researchers worked alongside a team from Oak Ridge National Laboratory in Tennessee and used neutron scattering techniques to look for evidence of electron fractionalization in alpha-ruthenium chloride - a material that's structurally similar to graphene.

This also allowed them to measure the signatures of Majorana fermions for the first time by illuminating the material with neutrons, and then observing the pattern of ripples that the neutrons produced when scattered from the sample. 

These patterns were exactly what they'd expect to see based on the main theoretical model of quantum spin liquid, confirming for the first time that they'd seen evidence of it happening in a material.

"This is a new addition to a short list of known quantum states of matter," said Knolle.

 

"It's an important step for our understanding of quantum matter," added Kovrizhin. "It's fun to have another new quantum state that we've never seen before - it presents us with new possibilities to try new things."

Some of those new things involve quantum computers - which would be exponentially faster than regular computers - so even though all of this sounds pretty theoretical, they could actually have some really exciting potential applications.

The results (Proximate Kitaev Quantum Spin Liquid Behavior in a Honeycomb Magnet) have been published in Nature Materials.