2015/08/31 by Seung Su Baik, Keun Su Kim, Yeonjin Yi +1 · 2 citations
Materials Science · Physics and Astronomy · #2D Materials and Applications #Band gap #Berry connection and curvature #Condensed matter physics #Dirac (video compression format) #Dirac fermion #Doping #Geometric phase #Geometry #Graphene #Graphene research and applications #Massless particle #Phase (matter) #Physics #Quantum mechanics #Semiconductor #Semimetal #Topological Materials and Phenomena #Zigzag #cond-mat.mtrl-sci
paper · pdf · doi:10.1021/acs.nanolett.5b04106
published as Nano Letters 15, 7788 (2015)
openalex publication_date 2015/11/17 · arxiv created 2015/12/07 · arxiv updated 2015/12/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Thin flakes of black phosphorus (BP) are a two-dimensional (2D) semiconductor whose energy gap is predicted being sensitive to the number of layers and external perturbations. Very recently, it was found that a simple method of potassium (K) doping on the surface of BP closes its band gap completely, producing a Dirac semimetal state with a linear band dispersion in the armchair direction and a quadratic one in the zigzag direction. Here, based on first-principles density functional calculations, we predict that, beyond the critical K density of the gap closure, 2D massless Dirac Fermions (i.e., Dirac cones) emerge in K-doped few-layer BP, with linear band dispersions in all momentum directions, and the electronic states around Dirac points have chiral pseudospins and Berry's phase. These features are robust with respect to the spin-orbit interaction and may lead to graphene-like electronic transport properties with greater flexibility for potential device applications.