We consider open quantum systems described by a Hamiltonian of the type H0+λV, where λ is a small parameter. For such systems, we develop perturbative methods of solution of the corresponding Liouville-von Neumann and Schrödinger equations, by introducing “dissipation” operators which...

In this paper we study the quantum friction problem using the Hamiltonian of Caldirola-Kanai for a periodic Mathieu's type potential. In the sequel we study the lattice electron with friction we introduce a new effective Hamiltonian of the Caldirola-Kanai form for a Bloch's band. Finally we...

In this paper we calculate the Wigner distribution function and the partition function of Bloch electrons in uniform electric and magnetic fields with the help of the effective hamiltonian. We also calculate the magnetic and the electric susceptibilities. Using standard techniques of operator...

We show that all the linear and nonlinear evolution equations proposed so far for the density operator of open quantum systems admit a common algebraic structure in the form of a generalized commutator, which is the nonassociative product of a Lie-admissible algebra.