  In recent times, the Archimedean spiral structure has been considered as a
promising design element in construction for specific purposes and opening up
new possibilities in various applications. Its distinctive geometry exhibits a
continuous growth pattern with a constant separation between its successive
turns. One notable application of the Archimedean spiral structure in
metamaterial absorbers is in achieving broadband absorption. This paper
presents a comprehensive simulation of a tunable metamaterial absorber with an
Archimedean spiral structure in the frequency range of 60 to 600 terahertz. The
absorber's absorption spectrum is controlled by temperature variations that
induce changes in the conductivity of vanadium dioxide. The absorber is
composed of three layers: a bottom layer made of gold, a middle layer
consisting of vanadium dioxide, and an upper layer is constructed using a gold
cylinder, from which the Archimedean spiral with the same thickness as the gold
is subtracted. This research provides valuable insights into the design and
optimization of tunable metamaterial absorber.
