EurekAlert August 1, 2019
An international team of researchers (USA – Rutgers University, Japan) studied twisted bilayer graphene, created by superimposing two layers of graphene and slightly misaligning them. This creates a “twist angle” that results in a moiré pattern which changes rapidly when the twist angle changes and have a dramatic effect on the electronic properties of the material. This is because the moiré pattern slows down the electrons that conduct electricity in graphene and zip past each other at great speeds. At a twist angle of about 1.1 degrees – the so-called magic angle – the electrons come to an almost dead stop. The sluggish electrons start interacting with their neighbors to move in lockstep, they organize themselves into stripes that are robust and difficult to break. As a result, the material acquires amazing properties such as superconductivity or magnetism. The team found a close resemblance between this feature and similar observations in high-temperature superconductors. The research could help in the search for quantum materials and superconductors. Such materials would dramatically reduce energy consumption by making power transmission and electronic devices more efficient…read more. TECHNICAL ARTICLE
Correlated electrons as shown by the alternating positive (blue) and negative (red) charge stripes that formed in the “magic angle” twisted bilayer graphene seen in the image at left. CREDIT: Yuhang Jiang/Rutgers University-New Brunswick