Obtaining phase-optimized states from superpositions of coherent states in phase-sensitive attenuating/amplifying reservoirs

• Published in: Annals of physics Vol. 406; pp. 86 - 107
• Main Authors: Ferreira, C.J.S., Valverde, C., Avelar, A.T., Baseia, B., Malbouisson, J.M.C.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-07-2019
• Subjects: ANNIHILATION OPERATORS; APPROXIMATIONS; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; DISTRIBUTION; EIGENSTATES; ELECTROMAGNETIC FIELDS; MARKOV PROCESS; MICROWAVE RADIATION; Nonclassical properties; PHASE SPACE; Phase states; PURE STATES; Superposition of coherent states; TIME DEPENDENCE; Wigner representation; WIGNER THEORY; Nonclassical properties; Wigner representation; Superposition of coherent states; Phase states
• ISSN: 0003-4916; 1096-035X
• DOI: 10.1016/j.aop.2019.03.027

In this paper we present new nonclassical states of a single mode of the electromagnetic field constructed by superpositions of coherent states distributed over a semi-straight line starting from the origin of the phase space. These states have highly concentrated phase distributions and can be useful as approximations of phase states. We propose feasible schemes to prepare such states in microwave high-Q cavities and as traveling modes. We investigate nonclassical properties and determine the Wigner functions of such pure states. Then we consider the system in contact with a reservoir, taking into account dissipation and gain processes in the Markovian approximation, and study the time-evolution of these states by solving the master equation in the Wigner representation. From explicit expressions of the time-dependent Wigner functions, we study the time-dependence of nonclassical properties and use the negativity of the Wigner function to analyze the disappearance of sub-Planck structures as time evolves.