Applications of the Density Matrix Formalism

P. R. Berman, Vladimir S. Malinovsky

M. Gong, M. Tohyama

Karl Blum

Edwin D. Becker

康治 伏見

Pasquale Di Bari, Shreya Pandit, Ye-Ling Zhou

We show that a density matrix formalism provides a useful description of non-adiabatic transitions in two-state quantum systems. Compared to a traditional Hamiltonian formalism, even in the absence of decoherence when there is full equivalence between the two, the density matrix formalism provides a convenient change of variables that yields a powerful general analytical solution. This solution nicely describes a transition regime between the well known Landau-Zener-Stuckelberg-Majorana (LZSM) approximation and the extremely non-adiabatic limit. Our results have very general applications, within a large variety of problems in quantum physics, neutrino physics, cosmology.