Semimetallic "Electride Bands" Derived from Interlayer Electrons in Quasi-Two-Dimensional Electride Y$_2$C

TL;DR

This study confirms that Y$_2$C is a quasi-two-dimensional electride with semimetallic bands originating from interlayer electrons, verified through angle-resolved photoemission spectroscopy aligning with theoretical predictions.

Contribution

First experimental verification of 2D electride states in Y$_2$C using ARPES, demonstrating the existence of electride bands from interlayer electrons.

Findings

Observation of semimetallic electride bands near the Fermi level

Confirmation of Y$_2$C as a quasi-2D electride

Electride bands derived from interlayer anionic electrons

Abstract

Two-dimensional (2D) electrides are a new concept material in which anionic electrons are confined in the interlayer space between positively charged layers. We have performed angle-resolved photoemission spectroscopy measurements on Y$_2$C, which is a possible 2D electride, in order to verify the formation of 2D electride states in Y$_2$C. We clearly observe the existence of semimetallic "electride bands" near the Fermi level, as predicted by ${ab}$ ${initio}$ calculations, conclusively demonstrating that Y$_2$C is a quasi-2D electride with electride bands derived from interlayer anionic electrons.