The foundation is named after Simons.
The surprising behavior of electrons in materials with an underlying triangular structure is explored in an Infographic. Lucy Reading-Ikkanda/Simons Foundation.
Physicists have finally found out why materials that look like tiles at the atomic level have strange properties.
The triangular-patterned materials can end up in three different phases at the same time, thanks to a combination of cutting-edge computational techniques. Each wrestling for dominance overlaps the competing phases. The material becomes more ordered when it is heated up.
The study's lead author is a research fellow at the Center for Computational Quantum Physics in New York City. The experimentalists didn't know what the individual electrons in the materials were doing. Our role as theorists is to understand what's happening.
Researchers can use the findings to develop materials for future electronics. The odd properties are indicative of an elusive state of matter that could be used in error-correcting quantum computing.
The new paper was co-authored by CCQ research fellow Riccardo Rossi, CCQ research scientist Miles Stoudenmire, and CCQ director Antoine Georges.
The electrons in the materials were studied. The properties of a material are determined by the electrons.
It is a monumental task to understand the collective behavior of electrons. Two particles become entangled with one another. They can't be treated differently even after they're separated.
The triangular lattice arrangement is fascinating because the behavior of electrons depends on the layout of the atoms. electrons have a spin which can point either up or down An electron might want to have a different spin direction than its neighbors. Someone is always going to be unhappy in a triangle with three atoms and two spin directions. The system doesn't know what to do. Physicists call thisgeometric frustration.
The behavior of materials with triangular lattices has previously been observed by experimentalists. A simple model was set up to see what the electrons were doing. Their model is a grid of triangles with each connecting point serving as a site for electrons. Each site can host up to two electrons if they have opposite spins. There were as many electrons as there were sites in the model.
electrons in a triangular lattice exhibit odd behavior The electrons try to organize themselves in three different ways. The animation shows the alternating columns, angles separated by 120 degrees and a twisting pattern in three dimensions. Lucy Reading-Ikkanda/Simons Foundation.
The model seemed simple, but calculating the collective electron behavior was difficult. Three different methods were combined to bring unique strengths to the problem. A recent cultural shift in the field of physics allows physicists to tackle thornier problems by using so many approaches.
The researchers could change the conditions in their model by raising or lowering the temperature. Higher temperatures cause the electrons to fluctuate more wildly. A stronger interaction strength causes electrons to settle into a single site.
The researchers ran their computations at different temperatures. The model transitioned from a metallic phase to an insulating phase. The phase was intriguing. Increasing temperature causes electrons to act with greater disorder. The electrons preferred to move as the thermostat rose in the triangular lattice.
The researchers discovered that the electrons were trying to organize themselves in three different ways. The material became more orderly as the temperature increased.
The electrons tried to create alternating columns of electrons in the first attempt.
The electrons were tilted in the second order. An electron's spin can point either up or down, but it can lean at an angle. In this case, the three electrons in each of the lattice's triangles orient themselves so that their angles are spread out, with each angle separated by 120 degrees.
The third order was the most exciting. The spin angles of the electrons were aligned so that they had a right-handed or left-handed twisting pattern. A state of matter called a chiral spin liquid could be seen in this setup. The phase is needed in quantum computers to avoid errors.
The model did not reveal all the secrets of triangular lattice materials. Some materials exhibit superconductivity, in which electrons flow freely without losing energy, which the researchers didn't observe. They plan to repeat their model with different quantities of electrons to see if superconductivity pops up.
"Now is a really exciting time because the methods we have allow us to actually make statements about these systems." In the last five years, these methods have become powerful enough to address the problems that were considered too hard in the past.
More information is available in the paper "Mott Insulating States with Competing Orders in the Triangular Lattice Hubbard Model, Physical Review X". There is a DOI titled "10.103/PhysRevX.11.041013".
The Physical Review X is in the journal.
It was provided by the Simons Foundation.
Physicists found a material that was a mixture of three different phases.
The document is copyrighted. Any fair dealing for the purpose of private study or research cannot be reproduced without written permission. The information provided is for educational purposes.
All Rights Reserved © 2024
