Creating and manipulating interfacial spin with giant magnetic response in 4$f$ antiferromagnets

Abstract

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 4$f$ antiferromagnetic TbScO${}_3$ 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 SrTiO${}_3$/LaTiO${}_3$/TbScO${}_3$ 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 SrTiO${}_3$/LaTiO${}_3$ interface are entirely determined by the metamagnetic phase transitions of the underlying TbScO${}_3$ substrate. Our results pave a novel route to engineer the spin polarization of low-dimensional electron systems in 4$f$ antiferromagnet-based heterostructures.

5 pages, 4 figures