Quantum materials (QMs) with strong correlation and non-trivial topology are indispensable to next-generation information and computing technologies. Exploitation of topological band structure is an ideal starting point to realize correlated topological QMs. Herein, we report that strain-induced symmetry modification in correlated oxide SrNbO3 thin films creates an emerging topological band structure. Dirac electrons in strained SrNbO3 films reveal ultra-high mobility (100,000 cm2/Vs), exceptionally small effective mass (0.04me), and non-zero Berry phase. More importantly, strained SrNbO3 films reach the extreme quantum limit, exhibiting a sign of fractional occupation of Landau levels and giant mass enhancement. Our results suggest that symmetry-modified SrNbO3 is a rare example of a correlated topological QM, in which strong correlation of Dirac electrons leads to the realization of fractional occupation of Landau levels.
@article{arxiv.2108.08408,
title = {Correlated Oxide Dirac Semimetal in the Extreme Quantum Limit},
author = {Jong Mok Ok and Narayan Mohanta and Jie Zhang and Sangmoon Yoon and Satoshi Okamoto and Eun Sang Choi and Hua Zhou and Megan Briggeman and Patrick Irvin and Andrew R. Lupini and Yun-Yi Pai and Elizabeth Skoropata and Changhee Sohn and Haoxiang Li and Hu Miao and Benjamin Lawrie and Woo Seok Choi and Gyula Eres and Jeremy Levy and Ho Nyung Lee},
journal= {arXiv preprint arXiv:2108.08408},
year = {2024}
}