Non-magnetic layers with a single symmetry-protected Dirac cone: Which additional dispersions must appear?

IF 1.8 4区物理与天体物理 Q2 PHYSICS, MULTIDISCIPLINARY

EPL Pub Date : 2024-09-12 DOI:10.1209/0295-5075/ad7317

V. Damljanović

引用次数: 0

Abstract

In two-dimensional (2D), non-magnetic materials, a single Dirac cone at high-symmetry point (HSP) of the Brillouin zone (BZ), akin to the one in graphenes’ band structure, cannot appear as the only quasiparticle at the Fermi level. Here we found two layer groups with time-reversal symmetry, among all possible both without and with spin-orbit coupling, that host one Dirac cone at HSP and we show which additional dispersions appear: a pair of Dirac lines on opposite BZ edges and a pair of Dirac cones that can be moved but not removed by symmetry preserving perturbations, on the other two BZ edges. We illustrate our theory by a tight-binding band structure and discuss real 2D materials that belong to one of the two symmetry groups. Finally, we single out smaller or bigger discrepancies among the published papers on the same or related topic.

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具有单一对称保护狄拉克锥的非磁层：必须出现哪些额外的色散？

在二维（2D）非磁性材料中，布里渊区（BZ）高对称点（HSP）上的单一狄拉克锥（类似于石墨烯带状结构中的狄拉克锥）不可能作为费米级的唯一准粒子出现。在这里，我们在所有可能的无自旋轨道耦合和有自旋轨道耦合的层组中发现了两个具有时间反转对称性的层组，它们在高粒子水平上容纳了一个狄拉克锥，我们还展示了出现的其他色散：一对狄拉克线位于相对的布里渊区边缘，一对狄拉克锥位于另外两个布里渊区边缘，它们可以移动，但不会被对称性扰动移除。我们用紧密结合的带状结构来说明我们的理论，并讨论了属于这两个对称组之一的真实二维材料。最后，我们列出了已发表的相同或相关主题论文中或大或小的差异。

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

EPL 物理-物理：综合

CiteScore

3.30

自引率

5.60%

发文量

332

审稿时长

1.9 months

期刊介绍： General physics – physics of elementary particles and fields – nuclear physics – atomic, molecular and optical physics – classical areas of phenomenology – physics of gases, plasmas and electrical discharges – condensed matter – cross-disciplinary physics and related areas of science and technology. Letters submitted to EPL should contain new results, ideas, concepts, experimental methods, theoretical treatments, including those with application potential and be of broad interest and importance to one or several sections of the physics community. The presentation should satisfy the specialist, yet remain understandable to the researchers in other fields through a suitable, clearly written introduction and conclusion (if appropriate). EPL also publishes Comments on Letters previously published in the Journal.