Entropy of quantum systems with linear dissipation

Vyacheslav Sergeevich Kirchanov

Ronit Mahapatra

Yang Xiao-ming

Based on quantum theory, an investigation is conducted on the evolution characteristics of linear entropies of 1) atoms, 2) two cavities and 3) atom-cavity system in the interaction process of two entangled dissipative cavities and a single two-level atom which runs through one of cavities. The effect of the dissipative constant and the coupling strength of interaction between atom and cavity field on all three linear entropies is discussed for the resonant case.The results show that all three linear entropies strongly depend on the dissipative constant of cavity and the coupling strength between cavity field and atoms. Furthermore, the dissipative constant and the strength of interaction between atoms and cavity field affect not only the amplitude of the oscillation of field quantum entropy evolution but also its periodicity.

Göran Lindblad

Zheng Tai-Yu

In this paper,by using J-C model and the density operator theory in interaction picture,the evolution features of linear entropy were studied in the system of two two-level Rydberg atom and two entangled dissipative cavities with single-photon resonant interaction.The derivation was done of the linear entropy formula of a single atom,a single cavity,as well as two atoms,two cavities,and analyzed how the cavity dissipation coefficients and the atom-cavity interaction coupling coefficient influenced the oscillation model and the evolution period of linear entropies.The evolution periods of all linear entropies are inversely proportional to the constant g,the cavity dissipation constants k1 and k2 influence the modes and the periods of the linear entropies' evolution.

Chao Dong

The evolution of the linear entropies of the field,atoms and field-atoms coupling system in the system of two completely identical two-level atoms inside a phase-damping cavity interacting with a coherent field under large detuning are investigated.The effects of atomic initial state,the mean photon number of the field and the dissipation coefficient on the above linear entropies are discussed.The results show that the linear entropies of both the field and the atom are strongly dependent on the atomic initial state,but the evolution of the linear entropy of the system is independent of the atomic initial preparation.With the increasing of the mean photon number,the linear entropies of field,atoms and field-atoms increase;And the larger the dissipation,the more rapid the linear entropies of the field and system tend to the certain degree of mixture,but the linear entropies of atoms don't vary with the dissipation coefficient.