Observation of Unpinned Two-Dimensional Dirac States in Antimony Single Layers with Phosphorene Structure

Abstract

The discovery of graphene has stimulated enormous interest in two-dimensional (2D) electron gas with linear band structure. 2D Dirac materials possess many intriguing physical properties such as high carrier mobility and zero-energy Landau level thanks to the relativistic dispersion and chiral spin/pseudospin texture. 2D Dirac states discovered so far are exclusively pinned at high-symmetry points of the Brillouin zone, for example, surface Dirac states at $\overline{\Gamma }$ in topological insulators Bi${}_2$Se(Te)${}_3$ and Dirac cones at $K$ and $K^{\prime }$ in graphene. In this work, we report the realization of 2D Dirac states at generic $k$-points in antimony atomic layers with phosphorene structure ($i.e.$ $\alpha$-antimonene). The unpinned nature enables versatile ways to control the locations of the Dirac points in momentum space. In addition, dispersions around the unpinned Dirac points exhibit intrinsically anisotropic behaviors due to the reduced symmetry of generic momentum points. These properties make the $\alpha$-antimonene films a promising platform for exploring interesting physics in unpinned 2D Dirac fermions that are distinct from the conventional Dirac states in graphene.

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References in corpus (7)

• The electronic properties of graphene
• Arsenene: Two-dimensional buckled and puckered honeycomb arsenic systems
• Electric Field Induced Topological Phase Transition in Two-Dimensional Few-layer Black Phosphorus
• The development of ferromagnetism in the doped topological insulator Bi2-xMnxTe3
• Merging of Dirac points in a two-dimensional crystal
• Origin of the energy bandgap in epitaxial graphene
• Quantum size effects, multiple Dirac cones and edge states in ultrathin Bi(110) films

Cited by in corpus (5)

• Photo-induced electronic and spin topological phase transitions in monolayer bismuth
• Movable Dirac Points with Ferroelectrics: Kink States and Berry Curvature Dipoles
• Mastering the growth of antimonene on Bi2Se3: strategies and insights
• Imaginary coupling induced Dirac points and group velocity control in non-reciprocal Hermitian Lattice
• Atomically thin obstructed atomic insulators with robust edge modes and quantized spin Hall effect