Time-reversal symmetry (TRS) protection is core to topological physics, yet its role in correlated oxides-typically non-topological-remains underexplored. This limit hampers the potential in engineering exotic quantum states by fusing TRS protection and the rich emergent phenomena in the oxide platform. Here, we report evidence of a TRS-protected subband at oxygen vacancy-free LaAlO3/SrTiO3 interfaces. This subband causes a low-field quantum oscillation with anomalous characters: exceptionally light electron mass, aperiodicity, and susceptibility to magnetic fields. All findings align with a Rashba model in which TRS-protected transport occurs along quasi-1D ferroelastic domain walls, which possess a Dirac band topology and a giant Rashba spin-orbit coupling, two orders stronger than the 2D interface. Our results deepen the understanding of SrTiO3-based electron systems, unveiling an appealing new platform for quantum engineering.
@article{arxiv.2505.02243,
title = {Time-Reversal Symmetry Protected Transport at Correlated Oxide Interfaces},
author = {Mengke Ha and Qing Xiao and Zhiyuan Qin and Dawei Qiu and Longbing Shang and Xinyi Liu and Pu Yan and Changjian Ma and Danqing Liu and Chengyuan Huang and Zhenlan Chen and Haoyuan Wang and Chang-Kui Duan and Zhaoliang Liao and Wei-Tao Liu and Yang Gao and Kecheng Cao and Jiangfeng Du and Guanglei Cheng},
journal= {arXiv preprint arXiv:2505.02243},
year = {2025}
}