A recent detailed study in Nature challenges our picture of how electrons behave in quantum matter. Using layers of tungsten ditelluride, researchers have identified electrons on two sides that act as a single phase — and in this process, they have created what researchers call a new electronic state of matter.
“This is a completely new concept,” said Sanfeng Wu, an assistant professor of physics at Princeton University and chief executive of the paper. “We were able to create a new electronic category with this test — basically, a new kind of metal structure.”
Our current understanding of the behavior of metal electrons can be explained by a theory that works well with two- and three-dimensional systems but breaks down when it describes the interaction of electrons in one place.
“This theory describes the majority of instruments we know,” said Wu. “It states that metal electrons, although highly intertwined, should behave like free electrons, except that they may have different values in many other things, such as weight and magnetic moment.”
In one-sided systems, however, this “Fermi liquid theory” replaces another theory, “Luttinger liquid theory,” to explain the interaction between electrons.
“The theory of Luttinger liquid provides the first step in understanding the interaction of electrons in one place,” Wu said. “The electrons in a single dimensional lattice are so closely linked that, in a sense, they begin to act as free electrons.”