Emergent superconductivity driven by Van Hove singularity in a Janus Mo2PS monolayer†

IF 2.9 3区化学 Q3 CHEMISTRY, PHYSICAL

Physical Chemistry Chemical Physics Pub Date : 2025-01-16 DOI:10.1039/D4CP04053H

Meng Tang, Wenyuan Zhang, Guochun Yang and Huiqiu Deng

引用次数: 0

Abstract

Two-dimensional (2D) Janus structures with the breaking of out-of-plane mirror symmetry can induce many interesting physical phenomena, and have attracted widespread attention. Herein, we propose a Mo₂PS monolayer with mirror asymmetry, identified by first-principles structural search calculations, which demonstrates high thermodynamic and dynamic stability. Our findings reveal that Mo 4d-orbitals dominate the metallicity, significantly enhancing the density of states near the Fermi level due to Van Hove singularities (VHSs), leading to the existence of phonon-mediated superconductivity. Notably, tensile strain elevates the critical temperature (T_c) nearly tenfold, driven by strong coupling between softened acoustic modes of Mo vibrations and a new saddle point VHS at point X. These results highlight that the Janus Mo₂PS monolayer serves as a promising candidate for 2D straintronic applications with desirable physical properties.

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Janus Mo2PS单层中Van Hove奇点驱动的涌现超导性

打破平面外镜像对称性的二维（2D）杰纳斯（Janus）结构可诱发许多有趣的物理现象，并已引起广泛关注。在此，我们提出了一种具有镜像不对称性的 Mo2PS 单层结构，并通过第一原理结构搜索计算确定了该结构，它表现出很高的热力学和动力学稳定性。我们的研究结果表明，Mo 4d-轨道在金属性中占主导地位，由于范霍夫奇点（VHS）的存在，显著提高了费米级附近的态密度，从而导致了声子介导超导的存在。值得注意的是，拉伸应变使临界温度（Tc）升高了近十倍，这是由于 Mo 振动的软化声学模态与 X 点的新鞍点 VHS 之间存在强耦合。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Physical Chemistry Chemical Physics 化学-物理：原子、分子和化学物理

CiteScore

5.50

自引率

9.10%

发文量

2675

审稿时长

2.0 months

期刊介绍： Physical Chemistry Chemical Physics (PCCP) is an international journal co-owned by 19 physical chemistry and physics societies from around the world. This journal publishes original, cutting-edge research in physical chemistry, chemical physics and biophysical chemistry. To be suitable for publication in PCCP, articles must include significant innovation and/or insight into physical chemistry; this is the most important criterion that reviewers and Editors will judge against when evaluating submissions. The journal has a broad scope and welcomes contributions spanning experiment, theory, computation and data science. Topical coverage includes spectroscopy, dynamics, kinetics, statistical mechanics, thermodynamics, electrochemistry, catalysis, surface science, quantum mechanics, quantum computing and machine learning. Interdisciplinary research areas such as polymers and soft matter, materials, nanoscience, energy, surfaces/interfaces, and biophysical chemistry are welcomed if they demonstrate significant innovation and/or insight into physical chemistry. Joined experimental/theoretical studies are particularly appreciated when complementary and based on up-to-date approaches.