Detecting two photons with one molecule
Saumya Biswas, S. J. van Enk · Physical Review A · 2021
Taking inspiration from the human eye, the authors propose using a five-level molecule to detect up to two photons of different frequency that arrive sequentially. They use two formalisms to develop this model: a density-matrix method to achieve analytical results and characterize the proposed detector, and a Hamiltonian method that they show is well suited for numerical calculations.