Band renormalization in monolayer MoS2 induced by multipole screening

초록

Dielectric screening plays a crucial role in shaping the electronic structure of two-dimensional (2D) materials. In 2D semiconductors, screened Coulomb interactions arising from the surrounding dielectric environment are known to induce band renormalization, which is typically understood as a rigid shift of the electronic bands. Here, we experimentally demonstrate that dielectric screening can also give rise to nonrigid, momentumdependent band renormalization. Using temperature-dependent angle-resolved photoemission spectroscopy, we observe pronounced changes in the electronic band structure of monolayer MoS2 on a highly oriented pyrolytic graphite substrate. The results indicate that temperature-driven variations in the effective interlayer separation modulate the dielectric screening experienced by monolayer MoS2. At room temperature, the screening behavior is well described by a momentum-independent monopole approximation, whereas at liquid-helium temperatures the screening evolves into a multipolelike regime, leading to momentum-dependent band shifts.

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