BiXO/BiIrO（X = Fe，Mn）铁电超晶格中的可调谷和自旋极化。

Tunable Valley and Spin Polarizations in BiXO/BiIrO (X = Fe, Mn) Ferroelectric Superlattices.

机构信息

Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, School of Science, Tianjin University , Tianjin 300354, China.

School of Electrical and Electronic Engineering, Tianjin University of Technology , Tianjin 300384, China.

出版信息

ACS Appl Mater Interfaces. 2018 Jan 31;10(4):3822-3829. doi: 10.1021/acsami.7b18379. Epub 2018 Jan 19.

DOI:10.1021/acsami.7b18379

PMID:29322771

Abstract

The generation and modulation on valley and spin degrees of freedom are essential for multifunctional electronic devices. Herewith, the electronic structures in BiXO/BiIrO (X = Fe, Mn) ferroelectric superlattices are studied by first-principles calculations with spin-orbital coupling. Different from the previous BiAlO/BiIrO system, both valley and spin polarizations in bilayered BiIrO are achieved in BiXO/BiIrO superlattices, where the spin polarization in the valley can be engineered by the spin orientation of Fe or Mn owing to the xy-plane orbitals. Especially, the relatively parallel and antiparallel directions of ferroelectric polarization in BiFeO and BiIrO can switch the valley injection in BiFeO/BiIrO superlattices. Overall, the tunable valley and spin polarizations in BiFeO/BiIrO ferroelectric superlattices pave a way for developing nonvolatile data memories and valley-spin devices.

摘要

谷自由度和自旋自由度的产生和调控对于多功能电子器件至关重要。在此，通过考虑自旋轨道耦合的第一性原理计算研究了 BiXO/BiIrO（X = Fe，Mn）铁电超晶格的电子结构。与之前的 BiAlO/BiIrO 体系不同，在 BiXO/BiIrO 超晶格中实现了双层 BiIrO 的谷和自旋极化，其中由于 xy 平面轨道，Fe 或 Mn 的自旋取向可以对谷中的自旋极化进行调控。特别是，BiFeO 和 BiIrO 中铁电极化的相对平行和反平行方向可以切换 BiFeO/BiIrO 超晶格中的谷注入。总之，BiFeO/BiIrO 铁电超晶格中可调谐的谷和自旋极化为开发非易失性数据存储器和谷-自旋器件铺平了道路。