Few-Body Systems, vol.62, 2021 (SCI-Expanded)
© 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH, AT part of Springer Nature.We investigated the relativistic dynamics of oppositely charged two fermions interacting with an external uniform magnetic field, without considering any charge-charge interaction between the fermions. We chose the interaction of each fermion with the external magnetic field in the symmetric gauge, and obtained a precise solution of the corresponding fully-covariant two-body Dirac equation that derived from Quantum Electrodynamics via Action principle. The dynamic symmetry of the system we deal with allowed us to determine the relativistic Landau levels of such a spinless composite system, without using any group theoretical method. As a result, we determined the eigenfunctions and eigenvalues of the corresponding two-body Dirac Hamiltonian.