Understanding superconductors better

In recent years, two-dimensional quantum materials have become a platform for the realization of novel correlated and topological phases of matter. An international team of researchers, including RWTH professor Dante Kennes from the Institute for Theoretical Solid State Physics, has published a study on correlated electronic phases in twisted bilayer transition metal dichalcogenides in nature materials journal.

In the article, the researchers show that the transition metal dichalcogenide (WSe2), which consists of a twisted bilayer, allows the realization of exotic correlated phenomena such as high Tc-type superconductivity without being subject to the geometric constraints that occur when twisted bilayer graphs are used.

In the search for superconductors that transport electricity without resistance, the researchers are studying two-dimensional materials to gain a better understanding of high-temperature superconductivity and other exotic material phases. Two-dimensional materials consist of only one atomic layer and can develop unexpected properties when placed on top of each other.

If two layers of the same material are stacked on top of each other with a slight twist, different changes in the electronic material properties are triggered depending on the angle of twist. Twisted bilayer graphs, for example, develop superconducting properties at high temperatures. Thus, it offers a promising platform for investigating exotic correlated phenomena, which, however, are only observed at certain twists, the so-called magic angles - a challenge for experimental implementation under real laboratory conditions.

In their study, researchers from RWTH Aachen University, the Max Planck Institute for the Structure and Dynamics of Matter, Columbia University, the Center for Computational Quantum Physics at the Flatiron Institute in the US, and the National Institute for Materials Science in Japan show that similar phenomena are also possible with the twisted bilayer transition metal dichalcogenide WSe2<7sub>, but without the limitations of magic angles. The study demonstrates that the WSe2 material is a highly flexible platform for developing electronic band structures. It material enables the detailed investigation of strongly correlated phenomena that would otherwise be inaccessible.

» Original publication

Source: RWTH Aachen University