  The approach to extend the notion of entanglement for characterizing the
properties of quantum correlations in the state of a single qudit is presented.
New information and entropic inequalities, such as the subadditivity condition,
strong subadditivity condition, and monotonicity of relative entropy for a
single qudit corresponding to an arbitrary spin state with spin j are
discussed. The idea to employ quantum correlations in the single-qudit state,
such as the entanglement, for developing a new quantum technique in quantum
computing and quantum communication is proposed. Examples of qutrit and qudit
with j = 3/2 are considered.
