Details

Autor(en) / Beteiligte

• Liu, Z. K.
• Jiang, J.
• Zhou, B.
• Wang, Z. J.
• Zhang, Y.
• Weng, H. M.
• Prabhakaran, D.
• Mo, S-K.
• Peng, H.
• Dudin, P.
• Kim, T.
• Hoesch, M.
• Fang, Z.
• Dai, X.
• Shen, Z. X.
• Feng, D. L.
• Hussain, Z.
• Chen, Y. L.

Titel

A stable three-dimensional topological Dirac semimetal Cd3As2

Ist Teil von

• Nature materials, 2014-07, Vol.13 (7), p.677-681

Ort / Verlag

London: Nature Publishing Group UK

Erscheinungsjahr

2014

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• A state of matter known as a three-dimensional Dirac semimetal has latterly garnered significant theoretical and experimental attention. Using angle-resolved photoelectron spectroscopy, it is shown that Cd 3 As 2 is an experimental realization of a three-dimensional Dirac semimetal that is stable at ambient conditions. Three-dimensional (3D) topological Dirac semimetals (TDSs) are a recently proposed state of quantum matter 1 , 2 , 3 , 4 , 5 , 6 that have attracted increasing attention in physics and materials science. A 3D TDS is not only a bulk analogue of graphene; it also exhibits non-trivial topology in its electronic structure that shares similarities with topological insulators. Moreover, a TDS can potentially be driven into other exotic phases (such as Weyl semimetals 1 , 7 , axion insulators 1 , 4 and topological superconductors 8 , 9 ), making it a unique parent compound for the study of these states and the phase transitions between them. Here, by performing angle-resolved photoemission spectroscopy, we directly observe a pair of 3D Dirac fermions in Cd 3 As 2 , proving that it is a model 3D TDS. Compared with other 3D TDSs, for example, β-cristobalite BiO 2 (ref.  3 ) and Na 3 Bi (refs  4 , 5 ), Cd 3 As 2 is stable and has much higher Fermi velocities. Furthermore, by in situ doping we have been able to tune its Fermi energy, making it a flexible platform for exploring exotic physical phenomena.