  Thermal transport property of homogeneous twisted molybdenum disulfide
(MoS$_2$) is investigated using non-equilibrium molecular dynamics simulations
with the state-of-art force fields. The simulation results demonstrate that the
cross-plane thermal conductivity strongly depends on the interfacial twist
angle, while it has only a minor effect on the in-plane thermal conductivity,
exhibiting a highly anisotropic nature. A frequency-decomposed phonon analysis
showed that both the cross-plane and in-plane thermal conductivity of MoS$_2$
are dominated by the low-frequency phonons below 15 THz. As the interfacial
twist angle increases, these low-frequency phonons significantly attenuate the
phonon transport across the interface, leading to impeded cross-plane thermal
transport. However, the in-plane phonon transport is almost unaffected, which
allows for maintaining high in-plane thermal conductivity. Additionally, our
study revealed the strong size dependence for both cross-plane and in-plane
thermal conductivities due to the low-frequency phonons of MoS$_2$. The maximum
in-plane to cross-plane thermal anisotropy ratio is estimated as 400 for
twisted MoS$_2$ from our simulation, which is in the same order of magnitude as
recent experimental results (~900). Our study highlights the potential of twist
engineering as a tool for tailoring the thermal transport properties of layered
materials.
