Another interesting feature of this ground state modification shown here is that it is not sensitive to the cavity frequency ω c as long as the photon frequency is not much smaller than the electronic energy gaps. This can be seen by analyzing Eq. 33, where the 0 i |0 j overlap is a function of χ/ω c (note that χ ∝ ω c such that χ/ω c is ω c independent), which is photon frequency independent. As such, the overlap 0 i |0 j is photon frequency independent, and the ground state modification also remains independent of photon frequency as long as the photon frequency is not much smaller than the electronic energy gaps. However, when hω c