Two-dimensional exciton-polariton interactions beyond the Born approximation
Abstract
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. We show the polariton interaction strength and Tan's contact both exhibit an anomalous enhancement at red photon-exciton detuning when the scattering length is large. Our predictions may provide a qualitatively correct guide for studies of exciton and polariton nonlinearities, and suggest a route to achieving strongly nonlinear polariton gases.
Cite
@article{arxiv.2004.05559,
title = {Two-dimensional exciton-polariton interactions beyond the Born approximation},
author = {Hui Hu and Hui Deng and Xia-Ji Liu},
journal= {arXiv preprint arXiv:2004.05559},
year = {2022}
}
Comments
6 pages, 3 figures + 8 pages of Supplemental Material; many-body calculations (Bogoliubov theory) using a bosonic model Hamiltonian