Researchers have investigated the conditions under which pseudomode models, a tool for describing open quantum systems, achieve thermalization to the Gibbs state. These models allow for an exact description of the interaction between a quantum system and a thermal bath, even under strong coupling. However, it has been observed that, in general, a system coupled to pseudomodes does not thermalize to the system's Gibbs state, which is unexpected in the asymptotically weak coupling limit, where thermodynamic intuition suggests otherwise.

The study focused on determining under what circumstances pseudomode models satisfy detailed balance, a fundamental requirement for reaching thermodynamic equilibrium and thus thermalization to the Gibbs state. It was also investigated how specific parameter choices can induce a "weak detailed balance," restricted to a particular frequency range. These findings are crucial for the construction of thermodynamically consistent pseudomode models.

The established results are relevant for developing models that require thermodynamic consistency, especially in contexts where the system-bath interaction is complex. The research also considered a combination of Hermitian and non-Hermitian pseudomodes to yield a flat effective-temperature profile, which could have implications for the design of quantum systems operating under thermal equilibrium conditions.