Nonsymmorphic symmetry engineering of correlated Dirac points

Quantum materials (QMs) with strong correlations and nontrivial topology are critical for advancing next-generation information technologies and microelectronics. Leveraging topological band structures provides a promising path to realize correlated topological QMs. However, directly observing such band structures in oxide materials to enable quantum transport remains a challenge. Our recent findings suggest that tuning oxygen octahedral symmetry (OOS) is crucial for creating topological band structures near the Fermi level. In this study, we synthesize 4d CaNbO₃ (CNO) films that has nonsymmorphic symmetry, leading to topological band structures and unique physical properties. The CNO films demonstrate exceptionally high electron mobility and magnetoresistance, attributed to linear band dispersion near the Fermi level. Additionally, we observe negative longitudinal magnetoresistance, indicative of a chiral anomaly, and complex oscillation behavior due to a combination of chiral anomaly and weak antilocalization.