  (Exo-)planets inherit their budget of chemical elements from a protoplanetary
disk. The disk temperature determines the phase of each chemical species, which
sets the composition of solids and gas available for planet formation. We
investigate how gap structures, which are widely seen by recent disk
observations, alter the thermal and chemical structure of a disk. Planet-disk
interaction is a leading hypothesis of gap formation and so such changes could
present a feedback that planets have on planet-forming material. Both the
planet gap-opening process and the disk thermal structure are well studied
individually, but how the gap-opening process affects disk thermal structure
evolution remains an open question. We develop a new modelling method by
iterating hydrodynamical and radiative transfer simulations to explore the
gap-opening feedback on disk thermal structure. We carry out parameter studies
by considering different planet locations rp and planet masses Mp. We find that
for the same rp and Mp, our iteration method predicts a wider and deeper gap
than the non-iteration method. We also find that the inner disk and gap
temperature from the iteration method can vary strongly from the non-iteration
or disk without planets, which can further influence dust-trap conditions,
iceline locations, and distribution of various ices, such as H2O, CO2, and CO
on large dust grains ("pebbles"). Through that, a gap-opening planet can
complicate the canonical picture of the non-planet disk C/O ratio and influence
the composition of the next generation of planetesimals and planets.
