Microscopic exceptional points in the post-selected open Jaynes--Cummings model (opens in new tab)

Phenomenological non-Hermitian Hamiltonians track selected signatures of complex reservoir dynamics, while post-selected no-jump effective Hamiltonians derived from microscopic open-system theory reveal the underlying system--reservoir physics. We derive such a Hamiltonian for the open Jaynes--Cummings model using a Moore--Penrose normalized $\mathrm{su}(2)$ representation that removes the vacuum-sector singularity and diagonalizes the full Hami...