  The Weyl-Wigner formalism for evaluating the intrinsic information of Dirac
bispinors as correlated qubits (localized) in a magnetic field is investigated
in the extension to statistical ensembles. The confining external field
quantizes the quantum correlation measures implied by the spin-parity qubit
structure of the Dirac equation in 3+1 dimensions, which simplifies the
computation of the entanglement quantifier for mixed states in relativistic
Landau levels. This allows for the evaluation of quantum and classical
correlations in terms of entropy measures for Dirac structures that are
eventually mixed. Our results are twofold. First, a family of mixed Gaussian
states is obtained in phase space, and its intrinsic correlation structure is
computed in closed form. Second, the partition function for the low-dimensional
Dirac equation in a magnetic field is derived through complex integration
techniques. It describes the low-temperature regime in terms of analytically
continued Zeta functions and the high temperature limit as a polynomial on the
temperature variable. The connection with lower dimensional systems is further
elicited by mapping the spin-parity qubits to valley-sublattice bispinors of
the low-energy effective Hamiltonian of graphene.
