In recent years there has been great interest towards optical cavities as a
tool to manipulate the properties and phases of embedded quantum materials. Due
to the Purcell effect, a cavity changes the photon phase space and thus the
rate of electromagnetic transitions within the material, modifying the exchange
rate of heat radiation with the photon environment. Here, I derive a simple
expression for the radiative heat power absorbed by the material, investigate
how it changes in the presence of a cavity and show that it is enhanced
dramatically for appropriate cavity geometries. I compare this effect with
typical energy dissipation processes, provide a criterion to establish its
impact on the temperature of a material coupled to the cavity and apply it to
1T-TaS2.Comment: 6+6 pages 3+3 figure