  Classical random matrix ensembles were originally introduced in physics to
approximate quantum many-particle nuclear interactions. However, there exists a
plethora of quantum systems whose dynamics is explained in terms of
few-particle (predominantly two-particle) interactions. The random matrix
models incorporating the few-particle nature of interactions are known as
embedded random matrix ensembles. In the present paper, we provide a brief
overview of these two ensembles and illustrate how the embedded ensembles can
be successfully used to study decoherence of a qubit interacting with an
environment, both for fermionic and bosonic embedded ensembles. Numerical
calculations show the dependence of decoherence on the nature of the
environment.
