Magnetic Phase Transition Induced Electronic Mirage: Decoding the Six-Petal Orbital Texture in Monolayer 1T-NbSe₂

Strong electron-lattice coupling in 1T-MX₂ (M = Nb, Ta; X = S, Se) enables diverse quantum phenomena. Using first-principles calculations, we reveal temperature-dependent orbital textures of midgap states in monolayer 1T-NbSe₂ with a star-of-David charge-density-wave superstructure. A mere 0.1% thermal lattice expansion drives a sharp nonmagnetic-to-ferromagnetic transition. In the ferromagnetic phase, midgap states localize at the supercell center, while in the nonmagnetic phase, high-energy Rydberg-like states generate weak in-gap signals and characteristic six-petal orbital patterns. These findings resolve long-standing theory-experiment discrepancies and establish Rydberg fingerprinting as a method to probe high-energy electronic structures via low-bias scanning tunneling spectroscopy, offering new insights into coupled electronic and magnetic degrees of freedom in two-dimensional transition metal dichalcogenides.