Exceptional points in the dynamics of open quantum systems

In this talk we will consider dissipative quantum systems that display exceptional points (EPs) in their dynamics. An EP is a point in parameter space in which several eigenvalues and eigenvectors of the matrix describing the dynamics of a system coalesce. We will analyze the signatures of these EPs in a 1D array of coupled harmonic oscillators and in a system of two coupled spins. We will show that the usual exponential decay of excitations presents polynomial corrections at the EP, and that interference windows emerge in which resonant absorption and emission are strongly inhibited.