3,491 research outputs found
Cluster persistence in one-dimensional diffusion--limited cluster--cluster aggregation
The persistence probability, , of a cluster to remain unaggregated is
studied in cluster-cluster aggregation, when the diffusion coefficient of a
cluster depends on its size as . In the mean-field the
problem maps to the survival of three annihilating random walkers with
time-dependent noise correlations. For the motion of persistent
clusters becomes asymptotically irrelevant and the mean-field theory provides a
correct description. For the spatial fluctuations remain relevant
and the persistence probability is overestimated by the random walk theory. The
decay of persistence determines the small size tail of the cluster size
distribution. For the distribution is flat and, surprisingly,
independent of .Comment: 11 pages, 6 figures, RevTeX4, submitted to Phys. Rev.
Orbital-selective Mott Transitions in a Doped Two-band Hubbard Model
We extend previous studies on orbital-selective Mott transitions in the
paramagnetic state of the half-filled degenerate two-band Hubbard model to the
general doped case, using a high-precision quantum Monte Carlo dynamical
mean-field theory solver. For sufficiently strong interactions,
orbital-selective Mott transitions as a function of total band filling are
clearly visible in the band-specific fillings, quasiparticle weights, double
occupancies, and spectra. The results are contrasted with those of single-band
models for similar correlation strengths.Comment: 12 pages, 12 figure
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