Persistence of charge density wave against variation of band structures in V_xTi_1−xSe₂ (x = 0–0.1)

Charge density wave (CDW) is a phenomenon that occurs in materials, accompanied by changes in their intrinsic electronic properties. The study of CDW and its modulation in materials holds tremendous significance in materials research, as it provides a unique approach to controlling the electronic properties of materials. TiSe₂ is a typical layered material with a CDW phase at low temperatures. Through V substitution for Ti in TiSe₂, we tuned the carrier concentration in V_xTi_1−xSe₂ to study how its electronic structures evolve. Angle-resolved photoemission spectroscopy (ARPES) shows that the band-folding effect is sustained with the doping level up to 10%, indicating the persistence of the CDW phase, even though the band structure is strikingly different from that of the parent compound TiSe₂. Though CDW can induce the band fold effect with a driving force from the perspective of electronic systems, our studies suggest that this behavior could be maintained by lattice distortion of the CDW phase, even if band structures deviate from the electron-driven CDW scenario. Our work provides a constraint for understanding the CDW mechanism in TiSe₂, and highlights the role of lattice distortion in the band-folding effect.