Computational Design of Flexible Electrides with Non-trivial Band Topology

Abstract

Electrides, with their excess electrons distributed in crystal cavities playing the role of anions, exhibit a variety of unique electronic and magnetic properties. In this work, we employ the first-principles crystal structure prediction to identify a new prototype of A${}_3$B electride in which both interlayer spacings and intralayer vacancies provide channels to accommodate the excess electrons in the crystal. This A${}_3$B type of structure is calculated to be thermodynamically stable for two alkaline metals oxides (Rb${}_3$O and K${}_3$O). Remarkably, the unique feature of multiple types of cavities makes the spatial arrangement of anionic electrons highly flexible via elastic strain engineering and chemical substitution, in contrast to the previously reported electrides characterized by a single topology of interstitial electrons. More importantly, our first-principles calculations reveal that Rb${}_3$O is a topological Dirac nodal line semimetal, which is induced by the Rb-$s$ $\to$ O-$p$ band inversion at the general electronic k momentums in the Brillouin zone associated with the intersitial electric charges. The discovery of flexible electride in combining with topological electronic properties opens an avenue for electride design and shows great promises in electronic device applications.

arXiv comment15 pages, 12 figures

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Cited by in corpus (8)

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• Ferromagnetic Weyl Fermions in Two-Dimensional Layered Electride Gd${}_2$C
• Application of topological quantum chemistry in electrides
• Six-fold Excitations in Electrides
• Hidden Weyl Fermions in Paramagnetic Electride Y${}_2$C
• Switchable Atomically Thin 2D Electrides from First-principles Prediction
• First-Principles Design of Halide-Reduced Electrides: Magnetism and Topological Phases
• First-principles Investigation of Electrides Derived from Sodalites