Creating and manipulating spin polarization in low-dimensional electron systems (such as two-dimensional electron gases) is fundamentally essential for spintronic applications, which is yet a challenge to date. In this work, we establish the metamagnetic phase diagram of 4f antiferromagnetic TbScO3 and reveal its giant magnetic response to sub-tesla magnetic field, which has not been reported thus far. Utilizing this giant magnetic response, we demonstrate that the spin polarization of two-dimensional electron gas in SrTiO3/LaTiO3/TbScO3 heterostructure can be manipulated successfully in aid of interfacial 3\textit{d}-4\textit{f} exchange interaction. Remarkably, the hysteretic magnetoresistances of two-dimensional electron gas at the SrTiO3/LaTiO3 interface are entirely determined by the metamagnetic phase transitions of the underlying TbScO3 substrate. Our results pave a novel route to engineer the spin polarization of low-dimensional electron systems in 4f antiferromagnet-based heterostructures.
@article{arxiv.2001.06664,
title = {Creating and manipulating interfacial spin with giant magnetic response in 4$f$ antiferromagnets},
author = {Ruyi Zhang and Yujuan Pei and Yang Song and Jiachang Bi and Jingkai Yang and Junxi Duan and Yanwei Cao},
journal= {arXiv preprint arXiv:2001.06664},
year = {2020}
}