On Macroscopic Quantum Coherence with Synchronized Atoms and Molecules: Superradiance

Abstract

The collective behavior of quantum particles is one of the most intriguing phenomena in quantum optics. In particular, superradiance refers to spontaneous collective emissions from a group of quantum particles behaving collectively as a whole due to the buildup of macroscopic quantum coherence. An important question is whether macroscopic quantum coherence is constructed by means of a quantum synchronization (i.e., a quantum analog of classical synchronization) or not. The purpose of this article is to draw attention to this question from the author’s perspective. A few selected studies relevant to synchronized atoms and molecules are discussed. The author concludes that collective behaviors of quantum particles may be formulated as quantum synchronizations, but extensive studies are still needed to confirm this hypothesis.

Dynamics of Wavefunction Decay: The Quantum Entanglement and the Measure Process

“…On the other hand, a perfect linear universal system would maintain c    as well as quantum correlations on global scale and would never allow the quantum decoupling between the system and the measuring apparatus necessary for the measure process. Furthermore, since the connection (A6.28) between the PMD and the MDD holds only at leading order of approximation of q  (i.e., slow relaxation process and small amplitude of fluctuations), in the case of large fluctuations (that can occur on time scale much longer than the relaxation one) q,t ) q,t )  ( ( can make transitions not described by (5.36) even from a stationary eigenstate to a generic superposition of states (e.g., following quantum synchronization [9]). In this case a new relaxation toward different stationary eigenstate will follow: The PMD q,t )  ( (5.34) describes the relaxation process in the time interval between two large fluctuations, but not the complete evolution of the system toward the statistical mixture.…”