Dissipation and decoherence in quantum systems

M Grigorescu

Philip C. E. Stamp

Michael B. Mensky

Decoherence aiid dissipation of a quantum system occurs due to its entanglement with the environment (reservoir) . In the course of interaction of the system with the reservoir information about the system is 'recorded' in the state of the reservoir. This is why influence of the reservoir on the system (i.e. the system's decoherence and dissipation) may be accounted in the framework of quantum theory of continuous measurements. Constructing such a theory with the help of restricted path integrals (RPI) gives a model-independent theory of decoherence and dissipation. The special role of information in decoherence and dissipation is explicitly revealed by this approach. This makes it possible to apply the RPI approach for the analysis of decoherence in quantum informatic devices.

Piotr Marecki

Subhashish Banerjee, Rupamanjari Ghosh

We study open quantum systems where the coupling between the system and its environment is of a quantum nondmolition (QND) type. Such a system undergoes decoherence without dissipation of energy. We obtain the master equation for the evolution of such a system under the influence of a squeezed thermal bath. From the master equation it can be seen explicitly that the process involves decoherence without any dissipation. We work out the decoherence causing term in the high and zero temperature limits and show that they match with known results in the different temperature regimes for the case of a thermal bath. We also make a comparison between the quantum statistical properties of QND and non-QND (i.e., involving decoherence as well as dissipation) types of evolution.

Lucas S. Marinho, O. P. de Sá Neto, Marcos Sampaio +2 more

Abstract In certain analyses of quantum systems, it is common to disregard the dissipation effect and focus solely on decoherence. This is because decoherence typically occurs on a much shorter timescale compared to dissipation. However, in order to gain insight into the role of dissipation, we examine the interference pattern in a double-slit experiment while considering both effects. To do so, we establish time scales for decoherence and dissipation and acknowledge the possibility of these effects occurring in close proximity. By comparing the relative intensity and fringe visibility between a purely decoherent model and a model that incorporates both decoherence and dissipation, we observe that when the time scales of decoherence and dissipation are similar, there exists a propagation time interval where dissipation contributes to a faster degradation of quantum features compared to the sole influence of decoherence. Hence, it is crucial to consider both decoherence and dissipation effects, especially when their time scales are closely aligned, to gain a comprehensive understanding of quantum behavior.