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Long-lived Quantum Coherence between Macroscopically Distinct States in Superradiance

Daniel Braun·Petr A. Braun·Fritz Haake
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Abstract

The dephasing influence of a dissipative environment reduces linear superpositions of macroscopically distinct quantum states (sometimes also called Schrödinger cat states) usually almost immediately to a statistical mixture. This process is called decoherence. Couplings to the environment with a certain symmetry can lead to slow decoherence. In this Letter we show that the collective coupling of a large number of two-level atoms to an electromagnetic field mode in a cavity that leads to the phenomena of superradiance has such a symmetry, at least approximately. We construct superpositions of macroscopically distinct quantum states decohering only on a classical time scale and propose an experiment in which the extraordinarily slow decoherence should be observable.

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Daniel Braun, Petr A. Braun, Fritz Haake. 1999-03-11. Long-lived Quantum Coherence between Macroscopically Distinct States in Superradiance. https://doi.org/10.1016/s0030-4018(99)00480-0

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