Giant Zeeman-type spin splitting of free electron/hole states on quasi-2D perovskite niobates: a theoretical prediction

Yi Zhou; Fei Zhou; Yong Liu; Zhonghong Lai; Mingqing Liao; Yudong Huang; Jingchuan Zhu

doi:10.1038/s41598-020-60653-8

Giant Zeeman-type spin splitting of free electron/hole states on quasi-2D perovskite niobates: a theoretical prediction

Sci Rep. 2020 Feb 28;10(1):3698. doi: 10.1038/s41598-020-60653-8.

Authors

Yi Zhou¹, Fei Zhou^{2

3}, Yong Liu^{1

4}, Zhonghong Lai⁵, Mingqing Liao¹, Yudong Huang⁶, Jingchuan Zhu^{7

8

9}

Affiliations

¹ School of Materials Science and Engineering, Harbin Institute of Technology, 150001, Harbin, China.
² School of Materials Science and Engineering, Harbin Institute of Technology, 150001, Harbin, China. angel.flyfly@hotmail.com.
³ MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, 150001, Harbin, China. angel.flyfly@hotmail.com.
⁴ National Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, 150001, Harbin, China.
⁵ Center of Analysis and Measurement, Harbin Institute of Technology, 150001, Harbin, China.
⁶ MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, 150001, Harbin, China.
⁷ School of Materials Science and Engineering, Harbin Institute of Technology, 150001, Harbin, China. fgms@hit.edu.cn.
⁸ National Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, 150001, Harbin, China. fgms@hit.edu.cn.
⁹ National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, 150001, Harbin, China. fgms@hit.edu.cn.

Abstract

We study the spin-orbit interaction of two-dimensional electron/hole gas (2DEGs/2DHGs) on quasi-2D potassium niobates (KNs) via first-principles calculations. The strong surface polarity changes the free surface states from 2DEGs to 2DHGs. The in-plane dipole maintained on 2D models leads to giant Zeeman-type spin splitting, as high as 566 meV for the (001)_c facet KN and 1.21 eV for the (111)_c facet KN. The thickness-dependent Zeeman-type spin splitting shows a linear relation with respect to 1/r, while the corresponding in-plane polarization quantum has a linear relation of 1/(2^0.5)with respect to a decrease in thickness. Interestingly, the 2DHGs with molecular-like orbital character is solely constituted by O 2p states, showing logic switchable behavior at extremely thin samples with enormous Zeeman-type splitting that can switch between insulator and conductor by opposite spin polarization.