Influence of Magnetic Field and LO Phonon Effect on Properties of Magnetopolarons and Qubit in Quantum Disks

Abstract

Influence of external magnetic field, longitudinal-optical (LO) phonon effect and thickness of quantum disks (QDs) on the properties of electron-LO phonon strong-coupling magnetopolarons and the qubit is studied by using Lee-Low-Pines-Huybrechts variational method. The expressions for the mean number of phonons of magnetopolaronsN, electron-LO phonon interaction energy E e−ph , energies of the ground and first-excited states E 0 and E 1 , oscillation period T 0 of qubits and probability distribution ρ of electrons are derived. Results of numerical calculations show that the mean number of phonons of the ground state of magnetopolarons is larger than that of the first-excited state, the mean number of phonons of magnetopolaronsN increases with increasing the cyclotron frequency ω c , confinement strength ω 0 and coupling strength α, but decreases and oscillates with increasing the thickness of QDs L; E e−ph is always negative, | E e-ph | of the ground state is larger than that of the first-excited state, and | E e-ph | increases with increasing ω c , ω 0 and α but decreases with increasing L; E 0 and E 1 increase with increasing ω c , ω 0 and α, but decrease with increasing L; T 0 increases with increasing ω 0 and L, but decreases with increasing α; ρ decreases and oscillates with increasing L, and decreases with increasing ω 0 ; the variations of T 0 and ρ with ω c and L are influenced by ω 0 and α significantly.