Details

Autor(en) / Beteiligte

• Sheng, Xian-Lei
• Chen, Cong
• Liu, Huiying
• Chen, Ziyu
• Yu, Zhi-Ming
• Zhao, Y X
• Yang, Shengyuan A

Titel

Two-Dimensional Second-Order Topological Insulator in Graphdiyne

Ist Teil von

• Physical review letters, 2019-12, Vol.123 (25), p.256402-256402, Article 256402

Ort / Verlag

United States: American Physical Society

Erscheinungsjahr

2019

Quelle

American Physical Society Journals

Beschreibungen/Notizen

• A second-order topological insulator (SOTI) in d spatial dimensions features topologically protected gapless states at its (d-2)-dimensional boundary at the intersection of two crystal faces, but is gapped otherwise. As a novel topological state, it has been attracting great interest, but it remains a challenge to identify a realistic SOTI material in two dimensions (2D). Here, based on combined first-principles calculations and theoretical analysis, we reveal the already experimentally synthesized 2D material graphdiyne as the first realistic example of a 2D SOTI, with topologically protected 0D corner states. The role of crystalline symmetry, the robustness against symmetry breaking, and the possible experimental characterization are discussed. Our results uncover a hidden topological character of graphdiyne and promote it as a concrete material platform for exploring the intriguing physics of higher-order topological phases.