Electronic characterization of the 1T-TaSe₂/1H-TaSe₂ bilayer heterostructure

Single layers of transition metal dichalcogenide materials (TMDs) provide an ideal platform to explore collective phenomena such as magnetism driven by strong electronic correlations. Here we report the electronic characterization of the low-lying electronic structure of the 1T-TaSe₂/1H-TaSe₂ bilayer heterostructure around the Fermi level (E_F) by means of high-resolution scanning tunneling spectroscopy at 300 mK. Our STS results show the clear presence of a two-peak structure separated by ~ 1meV and symmetric with respect to the Fermi level. The energy location of the resonances is found to vary with the application of a perpendicular magnetic and show two distinct regimes; a linear regime for high fields compatible with a Zeeman splitting and an intriguing non-linear regime for fields < 1 T. Our experimental observations along with specific calculations for this system enable us to paint a clear picture of the heavy fermion physics at play in this system.