Strain-tunable Dirac semimetal phase transition and emergent superconductivity in a borophane

Abstract

A two-dimensional (2D) Dirac semimetal with concomitant superconductivity has been long sought but rarely reported. It is believed that light-element materials have the potential to realize this goal owing to their intrinsic lightweight and metallicity. Here, based on the recently synthesized ${\beta }_{12}$ hydrogenated borophene [Science 371, 1143 (2021)], we investigate its counterpart named ${\beta }_{12}$-${\mathrm{B}}_5{\mathrm{H}}_3$. Our first-principles calculations suggest it has good stability. ${\beta }_{12}$-${\mathrm{B}}_5{\mathrm{H}}_3$ is a scarce Dirac semimetal demonstrating a strain-tunable phase transition from three Dirac cones to a single Dirac cone. Additionally, ${\beta }_{12}$-${\mathrm{B}}_5{\mathrm{H}}_3$ is also a superior phonon-mediated superconductor with a superconducting critical temperature of 32.4 K and can be further boosted to 42 K under external strain. The concurrence of Dirac fermions and superconductivity, supplemented with dual tunabilities, reveals ${\beta }_{12}$-${\mathrm{B}}_5{\mathrm{H}}_3$ is an attractive platform to study either quantum phase transition in 2D Dirac semimetal or the superconductivity or the exotic physics brought about by their interplay.

9 Pages, 5 Figures

References in corpus (24)

• The electronic properties of graphene
• Phonons and related properties of extended systems from density-functional perturbation theory
• Topological Semimetals
• Highly crystalline 2D superconductors
• Topological Phases in Two-Dimensional Materials: A Brief Review
• EPW: A program for calculating the electron-phonon coupling using maximally localized Wannier functions
• Dirac fermions in borophene
• Anisotropic Migdal-Eliashberg theory using Wannier functions
• Prediction of phonon-mediated superconductivity in borophene
• Predicted Unusual Magnetoresponse in Type-II Weyl Semimetals
• Towards Three-Dimensional Weyl-SurfaceSemimetals in Graphene Networks
• Stability and Strength of Atomically Thin Borophene from First Principles Calculations
• Magnetic breakdown and Klein tunneling in a type-II Weyl semimetal
• Topological superconductivity in Dirac semimetals
• Field-Selective Anomaly and Chiral Mode Reversal in Type-II Weyl Materials
• Superconducting properties of MgB2 from first principles
• Three-dimensional Pentagon Carbon with a genesis of emergent fermions
• Two-dimensional honeycomb borophene oxide: Strong anisotropy and nodal loop transformation
• Topological superconducting phase in high-Tc superconductor MgB2 with Dirac-nodal-line fermions
• Topological carbon materials: a new perspective
• Hexagonal supertetrahedral boron: A topological metal with multiple spin-orbit-free emergent fermions
• Dirac cones in Two-dimensional Borane
• 2D Ladder polyborane: an ideal Dirac semimetal with a multi-feld-tunable band gap
• Absence of sizable superconductivity in hydrogen boride: A first principles study