The enhancement of the |ν L population is very sensitive to the cavity frequency ω c , which needs to match the quantum vibration frequency ω 0 (i.e., the transition frequency of |ν L → |ν L ). A small deviation of ω c away from ω 0 will cause a much less significant enhancement of the |ν L population and thus the |ν R or |ν R populations (see Fig. ). Furthermore, when looking at the transient behaviors of population dynamics, one finds that when ω c = ω 0 , the |ν L and |ν R states have faster population gain than the cavity-free case. This is because the cavity mode promotes the |ν L → |ν L transition. This mechanism for the VSC-enhanced reactions has been previously discussed in the context of "RPV mode", in which it was found that an additional nuclear vibration mode can promote the proton transfer reaction rate constant. Here, our observation suggests that the cavity photon coordinate qc acts just like a "RPV mode". The only difference is that the cavity mode qc has a frequency ω c that can be easily (and continuously) tuned, whereas the frequency of RPV modes is not very easy to tune without doing chemical modifications.