Dissipating Decoherence

Malin Premaratne, Govind Prasad Agrawal

G.W. Ford, R.F. O'Connell

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.

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.

D. Dubbers, H.‐J. Stöckmann

Zuo, Jian

Decoherence is the suppression of the interference of quantum states. It plays important roles in the study of the quantum-classical transition. It is also the major obstacle in the implementation of various schemes of quantum computers. Decoherence can be affected by many factors. The interactions between quantum systems of interest and dissipative environments cause the extensively studied environment-induced-decoherence. Decoherence can also occur as the result of a temperature effect. A recent experiment investigated the engineering of decoherence, which involves applying an external field to the quantum system. In this thesis, we study the effect of an external field on decoherence in the case of a harmonic oscillator coupled to a heat bath by calculating its contribution to the attenuation coefficient, which is a measure of decoherence in coordinate space and involves directly observable probability distributions. It is found that, while non-random external force does not result in decoherence, a random external force can lead to intrinsic decoherence that does not require a dissipative environment. The attenuation coefficient for a free harmonic oscillator in a dissipative environment is also calculated using the solution of the initial value quantum Langevin equation. One of the key results obtained is that ”decoherence without dissipation” does not occur in the case of a free harmonic oscillator, in contrast to the case of a free particle.