This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Twistronics has become a new alchemy of materials. By choosing atomically thin layers, stacking them and changing their relative angle, researchers can create electronic behavior absent from the original ingredients.
Twisted graphene and transition metal dichalcogenides have already yielded superconductivity and fractional Chern insulators, states with fractionally charged excitations. One of physics' most active frontiers now has a moonshot ambition: to design entirely new forms of quantum matter. New families of twisted materials have repeatedly brought new rules for how electrons move and interact—a different Hamiltonian—and new kinds of quantum simulators.
The team's recent Nature study of M-point twisting illustrates how changing the starting electronic structure opens different physics. Exploring other atomic architectures could therefore uncover quantum states and models that today's familiar platforms cannot reach. Now, in two back-to-back papers to be published Sept. 24 in Science, an international collaboration provides both the building blocks and a guide to that vast search.
The first maps the electronic structures and topology of nearly 9,000 two-dimensional entries, whether topological or not. The second identifies more than 1,600 candidates for twisting, with different electronic starting points that could enable entirely new kinds of quantum simulators. "Every new family of twisted materials gives us a chance to ask a different question about quantum matter.
We want to move beyond the few platforms we know and explore the enormous range of physics that other layers and other twists could make possible," said B. Andrei Bernevig, a Princeton professor of physics and co-author of both studies. The first study extends topological quantum chemistry, a theory connecting a crystal's chemistry and symmetries to the topology of its electronic states, to nonmagnetic two-dimensional materials.
Symmetries are operations, such as rotations and reflections, that leave a crystal's atomic pattern unchanged. They help researchers determine how electronic waves can fit together throughout the crystal. Some patterns have a special property: Their topology cannot change without a fundamental alteration of the electronic structure.
Extract — continue reading at the source.
