Topological and superconducting properties of two-dimensional C6-2x(BN)x biphenylene network: a first-principles investigation

Fuente: arXiv
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Autori principali: Yang, Guang F., Song, Hong X., Wang, Dan, Wang, Hao, Geng, Hua Y.
Natura: Preprint
Pubblicazione: 2024
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author Yang, Guang F.
Song, Hong X.
Wang, Dan
Wang, Hao
Geng, Hua Y.
author_facet Yang, Guang F.
Song, Hong X.
Wang, Dan
Wang, Hao
Geng, Hua Y.
contents First-principles calculations have been used to investigate the electronic and topological properties of the two-dimensional C6-2x(BN)x biphenylene network, a graphene-like structure composed of not only hexagonal ring but also octagonal and square rings. Nontrivial topological properties have been found in two of them, with a stoichiometry of C4BN and C2(BN)2. The former C4BN is predicted to be a type-II Dirac semimetal with a superconducting critical temperature Tc=0.38K, which is similar to the pure carbon biphenylene network (C-BPN). The latter shows a novel isolated edge state exists between the conduction and valence bands. By regulation of strains and virtual-crystal approximation calculations, we found the annihilation of two pairs of Dirac points (DPs) in the non-high symmetric region (non-HSR) causes the two corresponding edge states stick together to generate this isolated edge state. In addition, we found that one pair of DPs arises from the shift of DPs in the C-BPN, while another new pair of DPs emerges around the Time Reversal Invariant Momenta (TRIM) point X due to the doping of boron and nitrogen. We constructed a tight-binding (TB) model to reveal the mechanism of forming the isolated edge state from the C-BPN to C2(BN)2. This study not only demonstrates the existence and mechanism of forming the isolated edge state in semimetals, but also provides an example in which the DPs can move away from the high-symmetry region.
format Preprint
id arxiv_https___arxiv_org_abs_2402_15801
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Topological and superconducting properties of two-dimensional C6-2x(BN)x biphenylene network: a first-principles investigation
Yang, Guang F.
Song, Hong X.
Wang, Dan
Wang, Hao
Geng, Hua Y.
Materials Science
Superconductivity
Applied Physics
Computational Physics
Quantum Physics
First-principles calculations have been used to investigate the electronic and topological properties of the two-dimensional C6-2x(BN)x biphenylene network, a graphene-like structure composed of not only hexagonal ring but also octagonal and square rings. Nontrivial topological properties have been found in two of them, with a stoichiometry of C4BN and C2(BN)2. The former C4BN is predicted to be a type-II Dirac semimetal with a superconducting critical temperature Tc=0.38K, which is similar to the pure carbon biphenylene network (C-BPN). The latter shows a novel isolated edge state exists between the conduction and valence bands. By regulation of strains and virtual-crystal approximation calculations, we found the annihilation of two pairs of Dirac points (DPs) in the non-high symmetric region (non-HSR) causes the two corresponding edge states stick together to generate this isolated edge state. In addition, we found that one pair of DPs arises from the shift of DPs in the C-BPN, while another new pair of DPs emerges around the Time Reversal Invariant Momenta (TRIM) point X due to the doping of boron and nitrogen. We constructed a tight-binding (TB) model to reveal the mechanism of forming the isolated edge state from the C-BPN to C2(BN)2. This study not only demonstrates the existence and mechanism of forming the isolated edge state in semimetals, but also provides an example in which the DPs can move away from the high-symmetry region.
title Topological and superconducting properties of two-dimensional C6-2x(BN)x biphenylene network: a first-principles investigation
topic Materials Science
Superconductivity
Applied Physics
Computational Physics
Quantum Physics
url https://arxiv.org/abs/2402.15801