Quantum decoherence mechamism in atom-molecule – collisions: NO-Ar.

In modern physics, quantum decoherence, a subject still under debate, is viewed as the mechanism responsible for the quantum-to-classical transition as the initially prepared quantum state interacts with its environment in an irreversible manner. As expected, one of the most common mechanisms responsible of the macroscopically observed decoherence involves collisions of an atom or molecule, initially prepared in a coherent superposition of states, with gas particles. In this work, a coherent superposition of quantum internal states of NO molecules is prepared by the interaction between the molecule with both a static and a radiofrequency electric field. Subsequently, NO+Ar collision decoherence experiments, are investigated by measuring the loss of coherence as a function of the number of collisions. Data analysis in the light of the interaction potential of the collisional partners allowed us to unravel the molecular mechanisms responsible for the loss of coherence in the prepared NO quantum superposition of internal states. The relevance of the present work relies on several aspects. On the one hand, the use of radio-waves introduces a new way for the production of coherent beams. On the other hand, the employed methodology, when satisfactorily applied to more collision systems, could be useful in designing experiments to reduce the environmental decoherence rate to levels necessary for quantum information processes. © 2012 American Institute of Physics.