For molecular polaritons, disorder and phonon timescales control the activation of dark states in the thermodynamic limit
Researchers used a hybrid MPS–HEOM method to simulate molecular polariton dynamics under static and dynamic disorder. They found that dynamic disorder is harder computationally because it activates non-collective degrees of freedom, specifically dark states. The study shows that phonon timescales dictate when the system reaches the thermodynamic limit, revealing a non-monotonic dependence on bath Markovianity.