Decoherence of Highly Mixed Macroscopic Quantum Superpositions

Abstract

It is known that a macroscopic quantum superposition (MQS), when it is exposed to environment, decoheres at a rate scaling with the separation of its component states in phase space. This is more or less consistent with the well known proposition that a more macroscopic quantum state is reduced more quickly to a classical state in general. Effects of initial mixedness, however, on the subsequent decoherence of MQSs have been less known. In this paper, we study the evolution of a highly mixed MQS interacting with an environment, and compare it with that of a pure MQS having the same size of the central distance between its component states. Although the decoherence develops more rapidly for the mixed MQS in short times, its rate can be significantly suppressed after a certain time and becomes smaller than the decoherence rate of its corresponding pure MQS. In an optics experiment to generate a MQS, our result has a practical implication that nonclassicality of a MQS can be still observable in moderate times even though a large amount of noise is added to the initial state.

6 pages, 4 figures

References in corpus (5)

• Decoherence, einselection, and the quantum origins of the classical
• Dynamics of Nonlocality for A Two-Mode Squeezed State in Thermal Environment
• A measurement-based measure of the size of macroscopic quantum superpositions
• Transfer of Nonclassical Properties from A Microscopic Superposition to Macroscopic Thermal States in The High Temperature Limit
• Entanglement of mixed macroscopic superpositions: an entangling-power study

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