Spin polarization ground state of quasi-2D magneto-bipolarons in the strong-coupling limit

•The concept of magneto-polaron is introduced.•Polarization ground state of quasi-2D magneto-bipolarons are investigated in view of spin effect.•Spin polarization ground state in strong-coupling limit is studied by variational method of Pekar type.•I–VIII polar crystals and semiconductors can be described according to the models.

Based on Lee–Low–Pines unitary transformation, characteristics of spin polarization ground state of quasi-2D magneto-bipolarons in the strong-coupling limit have been investigated by using the variational method of Pekar type. The changes law of the ground state energy E0 and the mean number of phonon N‾ with the confinement strength ω0, permittivity ratio η, strength of electron–phonon coupling α, and cyclotron resonance frequency of magnetic field ωc   have been derived. The results show that mean number phonons N‾ of magnetic bipolarons increased with increment of α, ω0, and ωc. The energy of ground state of magneto-bipolarons is consisted of single-particle energy of two electrons Ee, Coulomb interaction energy between two electrons Ec, interaction energy of electron spin and magnetic field ES, and interaction energy between electrons and phonons Ee-ph. The energy Ee-ph was always less than zero, and the absolute value increases with increasing of α, ω0, and ωc, which is the favorable factor in the formation of bound state magneto-bipolarons. The Coulomb repulsive energy between restriction and electrons is against to the formation of bound state magneto-bipolarons, and the fine structure of ground state manifold is caused by interaction between the electron spin and magnetic field.