The Emergence of Classicality via Decoherence: Beyond the Caldeira-Legget Environment

Maximally predictive states, as defined in recent work by Zurek, Habib and Paz, are studied for more elaborate environment models than a linear coupling to an oscillator bath (which has become known as the Caldeira-Leggett model). An environment model which includes spatial correlations in the noise is considered in the non-dissipative regime. The Caldeira-Leggett model is also re-considered in the context of an averaging procedure which produces a completely positive form for the quantum master equation. In both cases, the maximally predictive states for the harmonic oscillator are the coherent states, which is the same result found by Zurek, Habib and Paz for the Caldeira-Legget environment.