Manipulating intermolecular interactions with the coupling between quantum fluctuations and the vacuum field

Abstract

The mechanical mode of molecules coupled to cavities exhibits many new hybridized quantum states. This process can occur even in the vacuum due to the ground state of electromagnetic field inside the cavity. In this paper, we focus on how vibrational strong coupling (VSC) of the cavity vacuum can modify intermolecular forces. We suggest two tactics for the van der Waals (vdW) force modifications with empty cavity. In the first scheme, we treat the van der Waals interaction as the fluctuation of the instantaneous dipole. The vacuum field inside the cavity modulates the energy level of the combined mechanical mode. Tuning the cavity mode, the interactions can be controlled by the optical spring effect. The second method is the modification by utilizing the VSC of the intermolecular interaction. Hence the phonon–photon correlation is studied, which is fundamental for describing intermolecular interactions in VSC. The quantum description is established in this work, and some interesting features appear in the spectroscopy and quantum thermodynamics.