Robust ferromagnetism and Weyl half-semimetal in a two-dimensional vanadium boride monolayer

Abstract

Topological and ferromagnetic features in two-dimensional (2D) materials have been attracting great interests due to their fantastic physical properties. 2D Weyl half-semimetals (WHSMs) become an excellent platform to study both...

Topological Nodal-Point Superconductivity in Two-Dimensional Ferroelectric Hybrid Perovskites

“…As shown in Figure a, a pair of nodal points exist along the Γ–X direction. We calculate the Berry phase (see the SI for calculation details) and obtain the results of +π and −π, or topological charge +1 and −1, respectively, for the left and right nodal points, demonstrating their nontrivial topology to be the same as the Weyl points in 2D. , The opposite sign corresponds to the opposite chirality of the two nodal points.…”

“…We calculate the Berry phase (see the SI for calculation details) and obtain the results of +π and −π, or topological charge +1 and −1, respectively, for the left and right nodal points, demonstrating their nontrivial topology to be the same as the Weyl points in 2D. 51,52 The opposite sign corresponds to the opposite chirality of the two nodal points. One hallmark of topological superconducting states is the emergence of gapless Majorana modes, which can be verified by constructing a 1D finite system and solving the corresponding BdG Hamiltonian.…”