El papel de las ciudades en el desarrollo sostenible: el caso del programa ciudad 21 en Andalucía (España)

El Programa Ciudad 21 en Andalucía (España) es un programa que brinda apoyo y asesoramiento a las ciudades y pueblos andaluces que manifiesten su compromiso para crear un plan local hacia la sostenibilidad adoptando una Agenda 21 Local (A21L). La A21L es un programa de actuación a través del cual los ayuntamientos realizan un diagnóstico de sus municipios y tras la realización de un plan de participación ciudadana, definen e implantan una serie de actuaciones que consigan la mejora económica, social y medioambiental de sus municipios. En este trabajo se analizan los factores impulsores y obstaculizadores de la implementación de este programa en los ayuntamientos andaluces. Las conclusiones obtenidas muestran recomendaciones para mejorar estos procesos extensibles a otras regiones que se enfrentan a retos similares para conseguir el desarrollo sostenible de los pueblos y ciudades del mundo.The City 21 Program in Andalusia (Spain) is a program that provides support and advice to cities and towns in Andalusia which demonstrate their commitment to create a local plan for sustainability by adopting Local Agenda 21 (LA21). LA21 is a program of action through which town councils make a diagnosis of their municipalities and, following a citizen participation plan, define and implement a series of interventions to achieve improved economic, social and environmental performance in their municipalities. In this paper, we analyze the drivers and hindering factors in the implementation of this program in the Andalusian municipalities. The conclusions offer recommendations to improve these processes that can be generalized to other regions facing similar challenges in the sustainable development of villages and towns around the world.Los autores agradecen a la Empresa de Gestión Medioambiental, S.A. (EGMASA), empresa pública de la Junta de Andalucía, el apoyo, colaboración y financiación del presente trabajo de investigación

Cavity-QED entangled photon source based on two truncated Rabi oscillations

We discuss a cavity-QED scheme to deterministically generate entangled photons pairs by using a three-level atom successively coupled to two single longitudinal mode high-Q cavities presenting polarization degeneracy. The first cavity is prepared in a well defined Fock state with two photons with opposite circular polarizations while the second cavity remains in the vacuum state. A half-of-a-resonant Rabi oscillation in each cavity transfers one photon from the first to the second cavity, leaving the photons entangled in their polarization degree of freedom. The feasibility of this implementation and some practical considerations are discussed for both, microwave and optical regimes. In particular, Monte Carlo wave function simulations have been performed with state-of-the-art parameter values to evaluate the success probability of the cavity-QED source in producing entangled photon pairs as well as its entanglement capability.Comment: 18 pages, 9 figures; submitted for the "Optical Quantum Information Science Special Issue" of JOSA

Cavity QED quantum phase gates for a single longitudinal mode of the intracavity field

A single three-level atom driven by a longitudinal mode of a high-Q cavity is used to implement two-qubit quantum phase gates for the intracavity field. The two qubits are associated with the zero- and one-photon Fock states of each of the two opposite circular polarization states of the field. The three-level atom mediates the conditional phase gate provided the two polarization states and the atom interact in a V-type configuration and the two-photon resonance condition is satisfied. Microwave and optical implementations are discussed with gate fidelities being evaluated against several decoherence mechanisms such as atomic velocity fluctuations or the presence of a weak magnetic field. The use of coherent states for both polarization states is investigated to assess the entanglement capability of the proposed quantum gates