  Understanding the mixing of open quantum systems is a fundamental problem in
physics and quantum information science. Existing approaches for estimating the
mixing time often rely on the spectral gap estimation of the Lindbladian
generator, which can be challenging to obtain in practice. We propose a novel
theoretical framework to estimate the mixing time of open quantum systems that
treats the Hamiltonian and dissipative part separately, thus circumventing the
need for a priori estimation of the spectral gap of the full Lindbladian
generator. The technique is based on the construction of an energy functional
inspired by the hypocoercivity of (classical) kinetic theory.
