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arXiv · 2111.15334

Unusual phase transition of layer-stacked borophene under pressure

Xiao-Ji Weng·QuanSheng Wu·Xi Shao·Oleg V. Yazyev·Xin-Ling He·Xiao Dong·Hui-Tian Wang·Xiang-Feng Zhou·Yongjun Tian
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Abstract

The 8-Pmmn borophene, a boron analogue of graphene, hosts tilted and anisotropic massless Dirac fermion quasiparticles owing to the presence of the distorted graphene-like sublattice. First-principles calculations show that the stacked 8-Pmmn borophene is transformed into the fused three-dimensional borophene under pressure, being accompanied by the partially bond-breaking and bond-reforming. Strikingly, the fused 8-Pmmn borophene inherits the Dirac band dispersion resulting in an unusual semimetal-semimetal transition. A simple tight-binding model derived from graphene qualitatively reveals the underlying physics due to the maximum preservation of graphene-like substructure after the phase transition, which contrasts greatly to the transformation of graphite into diamond associated with the semimetal-insulator transition.

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Xiao-Ji Weng, QuanSheng Wu, Xi Shao, Oleg V. Yazyev, Xin-Ling He, Xiao Dong, Hui-Tian Wang, Xiang-Feng Zhou, Yongjun Tian. 2021-11-30. Unusual phase transition of layer-stacked borophene under pressure. https://doi.org/10.1103/physrevb.105.235410

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