Finetuning ‘twistronics’ of 2D crystals

Nanowerk  December 4, 2020 Twistronics, tuning of twist angle controls the topology and electron interactions in 2D materials, is a rising research topic in physics in recent years. An international team of researchers (UK, China, Japan, Singapore) has developed a technique enabling twisted van der Waals heterostructures with dynamically tunable optical, mechanical, and electronic properties. Using this technique, they fabricated heterostructures where graphene is perfectly aligned with both top and bottom encapsulating layers of hexagonal boron nitride. The technique could be used in autonomous robotic manipulation of two-dimensional crystals to build van der Waals superlattices, which would allow accurate positioning, […]

Taking the guesswork out of twistronics

Nanowerk  July 27, 2020 An international team of researchers (USA – Harvard University, China) introduces theoretical concepts and methods for the processing of materials information, and as a case study, apply them to investigate the electronic structure of multi-layer graphene-based assemblies in a high-throughput fashion. They provide a critical discussion of patterns and trends in tight binding band structures and identify specific layered assemblies using low-dispersion electronic bands as indicators of potentially interesting physics like strongly correlated behavior. A combination of data-driven models for visualization and prediction is used to intelligently explore the materials space. This work more generally aims […]

Scientists apply ‘twistronics’ to light propagation and make a breakthrough discovery

Nanowerk  June 11, 2020 As recent research showed how superconductivity is achieved in a pair of stacked graphene layers that were rotated to the “magic twist angle” and careful control of rotational symmetries can unveil unexpected material responses. Now an international team of researchers (Singapore, USA – City University of New York, Australia, China) has discovered that an analogous principle can be applied to manipulate light in highly unusual ways. They stacked two thin sheets of molybdenum trioxide and rotated one of the layers with respect to the other. When the materials were excited by a tiny optical emitter, they […]