Commutator Matrix in Phase Space Mapping Models for Nonadiabatic Quantum Dynamics

Nonadiabatic Geometric Phase in Quaternionic Hilbert Space

We develop the theory of the nonadiabatic geometric phase, in both the Abelian and non-Abelian cases, in quaternionic Hilbert space.

Quantum phase space distributions in thermofield dynamics

It is shown that the the quantum phase space distributions corresponding to a density operator ρ can be expressed, in thermofield dynamics, as overlaps between the state | ρ > and ”thermal” coherent states. The usefulness of this approach is brought out in the context of a master equation describing a nonlinear oscillator for which exact expressions for the quantum phase distributions for an ar...

On matrix elements of phase-angular momentum commutator in Hilbert space of arbitrary dimensions

We discuss correspondence between the predictions of quantum theories for rotation angle formulated in infinite and finite dimensional Hilbert spaces, taking as example, the calculation of matrix elements of phaseangular momentum commutator. A new derivation of the matrix elements is presented in infinite space, making use of a unitary transformation that maps from the state space of periodic f...

Phase space dynamics of overdamped quantum systems

The phase space dynamics of dissipative quantum systems in strongly condensed phase is considered. Based on the exact path integral approach it is shown that the Wigner transform of the reduced density matrix obeys a time evolution equation of Fokker-Planck type valid from high down to very low temperatures. The effect of quantum fluctuations is discussed and the accuracy of these findings is t...

Semiclassical Nonadiabatic Dynamics with Quantum Trajectories