Two-dimensional exciton-polariton interactions beyond the Born approximation

Understand

We provide a many-body theory for the interactions of two-dimensional excitons and polaritons beyond the Born approximation.

• Taking into account Gaussian quantum fluctuations via the Bogoliubov theory, we find that the two-body interaction strength in two-dimensions has an inverse logarithmic dependence on the scattering length and ground state energy.
• This leads to a vanishing exciton interaction strength in the zero-momentum limit but a finite polariton interaction strength due to strong light-matter coupling.
• We also derive the exact Tan relations for exciton-polaritons and calculate Tan's contact coefficient.