Coherent states nonlinear oscillator generation

The above results are applied to a harmonic oscillator coupled to a two-level system, that serves as the repeatedly measured ancilla. Relatively sparse measurements are shown to destroy the coherence of the oscillator whereas, in the Zeno-limit, the coherence is preserved for all times. This is demonstrated by a periodic generation of a Schrodinger cat-like state. The decoherence process is highly nonlinear in the initial state amplitude and the decoherence time decreases rapidly for increasing amplitude. 

II. FD Coherent States Generated by Nonlinear Oscillator Systems... 

However, we concentrate here on the generation methods in which we are able to get directly the FD quantum state desired. Namely, we shall describe the models involving quantum nonlinear oscillator driven by an external field [11-13,22]. For this class of systems we are able to get the quantum states that are very close for instance, to the FD coherent states [2,3] or to the FD squeezed vacuum [10]. 

II. FD COHERENT STATES GENERATED BY NONLINEAR OSCILLATOR SYSTEMS... 

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