A new phase of matter revealed in breakthrough physics by scientists who designed a frustration machine – The Debrief

The discovery of a new phase of matter has been heralded by a team of physicists, who made the breakthrough following the creation of a new device they characterize as a frustration machine.

In our daily lives, the three most common phases of matter that most of us encounter are solids, liquids and gases. Plasmas also occur in a variety of everyday circumstances, from lightning strikes during thunderstorms to welding arcs and plasmas inside tubes that light up neon signs.

However, there are a variety of conditions beyond what we normally experience on Earth, where matter can take on very different forms than we are used to seeing. These can occur with things that are infinitely small or possess very low energy states, as well as at very low temperatures close to absolute zero.

Now, Tigran Sedrakyan, assistant professor at the University of Massachusetts, and team document a new phase of matter similar to what it looks like under such extreme conditions, they call the bose-liquid chiral state, as reported recently in a paper they have published in the magazine Nature.

Within a given system, particles collide with each other, resulting in effects that scientists are usually very good at predicting. For example, if you roll a bowling ball across a set of pins, a predictable pattern is likely to emerge if the ball hits near its center, knocking surrounding pins over in every direction. In physics, this is an example of our understanding that the effects we observe are related to particles colliding with each other.

However, the quantum world can behave very differently as a frustrated quantum system can produce an infinite number of possibilities based on the interaction of particles, some of which can lead to very unique quantum states.

These types of quantum states have been the focus of Sedrakyans for several years, which include what is known as band degeneration, ditch bands, or kinetic frustration, which occur in quantum matter during strong interactions.

According to Sedrakyan and his colleagues, their investigations of ditch band phenomena yielded an interesting observation, which they characterize as an unconventional time-reversal symmetry that disrupts the excitonic ground state under deranged electron and hole densities.

Put simply, what the team has essentially done is the equivalent of designing a semiconductor device that works like a frustration machine by stacking a top semiconductor layer through which electrons are able to move freely and a bottom layer with holes through which electrons are able to move freely. electrons move occasionally. The two layers are then placed within a single atom’s width of each other.

Sedrakyan likens the resulting movement of electrons to a game of musical chairs, in which imbalances in the number of available electron holes are specifically designed to frustrate them.

Instead of every electron having a chair to go to, they now have to climb up and have a lot of chances, Sedrakyan said in a statement.

The resulting frustration is what produces the new chiral edge state, which produces several unique features. One is that when temperatures approaching absolute zero are reached with quantum matter in a chiral state, the electrons start behaving in predictable patterns as they freeze. The spin of electrons under such conditions cannot be altered even through collisions with other particles or the presence of magnetic fields, a property that has several unique potential applications.

[T]The state is very robust to external perturbations, such as, for example, clutter, dirt, temperature, fluctuations, all these kinds of things that normally severely affect the state of matter, Sedrakyan said in a statement.

However, observing the bose-liquid chiral state is not a simple task in itself. The team managed to do this with the combination of a theoretical framework and an experiment involving a strong magnetic field that allowed them to measure electrons as their position changed as they attempted to fill various holes in the bottom semiconductor layer of the frustration machine. which they had designed for such purposes.

The experiment was successful, revealing what is believed to be the first direct evidence of bose chiral liquid. The team says their discovery opens up a new direction for research into topological and related boson systems in solid states beyond their conventional phases and could have applications including more secure and reliable methods for coding digital information.

The team’s article, Excitonic topological order in unbalanced electron bilayers, appeared in the journal Nature on June 14, 2023.

Micah Hanks is managing editor and co-founder of The Debrief. He can be reached by email at[email protected]. Follow his work onwww.micahhanks.comand on Twitter:@MicahHanks.