Conversion of chirality to twisting via sequential one-dimensional and two-dimensional growth of graphene spirals.
Nature materials 23:3 (2024) 331-338
Abstract:
The properties of two-dimensional (2D) van der Waals materials can be tuned through nanostructuring or controlled layer stacking, where interlayer hybridization induces exotic electronic states and transport phenomena. Here we describe a viable approach and underlying mechanism for the assisted self-assembly of twisted layer graphene. The process, which can be implemented in standard chemical vapour deposition growth, is best described by analogy to origami and kirigami with paper. It involves the controlled induction of wrinkle formation in single-layer graphene with subsequent wrinkle folding, tearing and re-growth. Inherent to the process is the formation of intertwined graphene spirals and conversion of the chiral angle of 1D wrinkles into a 2D twist angle of a 3D superlattice. The approach can be extended to other foldable 2D materials and facilitates the production of miniaturized electronic components, including capacitors, resistors, inductors and superconductors.ARPES investigation of the electronic structure and its evolution in magnetic topological insulator MnBi2+2nTe4+3n family.
National science review 11:2 (2024) nwad313
Abstract:
In the past 5 years, there has been significant research interest in the intrinsic magnetic topological insulator family compounds MnBi2+2nTe4+3n (where n = 0, 1, 2 …). In particular, exfoliated thin films of MnBi2Te4 have led to numerous experimental breakthroughs, such as the quantum anomalous Hall effect, axion insulator phase and high-Chern number quantum Hall effect without Landau levels. However, despite extensive efforts, the energy gap of the topological surface states due to exchange magnetic coupling, which is a key feature of the characteristic band structure of the system, remains experimentally elusive. The electronic structure measured by using angle-resolved photoemission (ARPES) shows significant deviation from ab initio prediction and scanning tunneling spectroscopy measurements, making it challenging to understand the transport results based on the electronic structure. This paper reviews the measurements of the band structure of MnBi2+2nTe4+3n magnetic topological insulators using ARPES, focusing on the evolution of their electronic structures with temperature, surface and bulk doping and film thickness. The aim of the review is to construct a unified picture of the electronic structure of MnBi2+2nTe4+3n compounds and explore possible control of their topological properties.Distinct superconducting states in the pressure-induced metallic structures of topological heterostructure BiTe
Materials Today Physics Elsevier (2024) 101377
Nodal s± pairing symmetry in an iron-based superconductor with only hole pockets
Nature Physics Springer Nature (2024) 1-8
Pressure-induced superconductivity in the Zintl topological insulator SrIn2As2
Physical Review B American Physical Society (APS) 108:22 (2023) 224510