Details

Autor(en) / Beteiligte

• Honma, A.
• Takane, D.
• Souma, S.
• Yamauchi, K.
• Wang, Y.
• Nakayama, K.
• Sugawara, K.
• Kitamura, M.
• Horiba, K.
• Kumigashira, H.
• Tanaka, K.
• Kim, T. K.
• Cacho, C.
• Oguchi, T.
• Takahashi, T.
• Ando, Yoichi
• Sato, T.

Titel

Antiferromagnetic topological insulator with selectively gapped Dirac cones

Ist Teil von

• Nature communications, 2023-11, Vol.14 (1), p.7396-7396, Article 7396

Ort / Verlag

London: Nature Publishing Group

Erscheinungsjahr

2023

Link zum Volltext

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• Abstract Antiferromagnetic (AF) topological materials offer a fertile ground to explore a variety of quantum phenomena such as axion magnetoelectric dynamics and chiral Majorana fermions. To realize such intriguing states, it is essential to establish a direct link between electronic states and topology in the AF phase, whereas this has been challenging because of the lack of a suitable materials platform. Here we report the experimental realization of the AF topological-insulator phase in NdBi. By using micro-focused angle-resolved photoemission spectroscopy, we discovered contrasting surface electronic states for two types of AF domains; the surface having the out-of-plane component in the AF-ordering vector displays Dirac-cone states with a gigantic energy gap, whereas the surface parallel to the AF-ordering vector hosts gapless Dirac states despite the time-reversal-symmetry breaking. The present results establish an essential role of combined symmetry to protect massless Dirac fermions under the presence of AF order and widen opportunities to realize exotic phenomena utilizing AF topological materials.