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arXiv · 2409.18400

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

Chengyong Zhong·Xuelian Li·Peng Yu
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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 $β_{12}$ hydrogenated borophene [Science 371, 1143 (2021)], we investigate its counterpart named $β_{12}$-$ \rm {B_5H_3}$. Our first-principles calculations suggest it has good stability. $β_{12}$-$ \rm {B_5H_3}$ is a scarce Dirac semimetal demonstrating a strain-tunable phase transition from three Dirac cones to a single Dirac cone. Additionally, $β_{12}$-$ \rm {B_5H_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 $β_{12}$-$ \rm {B_5H_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.

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Chengyong Zhong, Xuelian Li, Peng Yu. 2024-09-27. Strain-tunable Dirac semimetal phase transition and emergent superconductivity in a borophane. https://doi.org/10.1038/s42005-024-01523-x

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