2003/01/31 by Stephane Nonnenmacher
Physics and Astronomy · #nlin.CD #quant-ph
paper · pdf · doi:10.1088/0951-7715/16/5/309
published as Nonlinearity 16, 1685-1713 (2003) · 35 pages, 6 .eps figures, to be published in Nonlinearity. I added some references and comments
arxiv created 2003/06/06 · arxiv updated 2009/11/30
We study classical and quantum maps on the torus phase space, in the presence of noise. We focus on the spectral properties of the noisy evolution operator, and prove that for any amount of noise, the quantum spectrum converges to the classical one in the semiclassical limit. The small-noise behaviour of the classical spectrum highly depends on the dynamics generated by the map. For a chaotic dynamics, the outer spectrum consists in isolated eigenvalues (``resonances'') inside the unit circle, leading to an exponential damping of correlations. On the opposite, in the case of a regular map, part of the spectrum accumulates along a one-dimensional ``string'' connecting the origin with unity, yielding a diffusive behaviour. We finally study the non-commutativity between the semiclassical and small-noise limits, and illustrate this phenomenon by computing (analytically and numerically) the classical and quantum spectra for some maps.