Influence of an External Magnetic Field on Polaronic Properties in an Asymmetric Quantum Dot

Abstract

An asymmetric quantum dot with shape anisotropy is selected as the theoretical model. By combining the linear combination operator method with the unitary transformation method, we theoretically derive an expression for the ground-state energy of a polaron in an asymmetric quantum dot, where this energy undergoes Zeeman splitting. In a weak magnetic field, the interaction between the spin magnetic moment and the magnetic field induces a splitting of the polaron energy into two components, with the Zeeman splitting energy being proportional to the magnetic field strength. The functional relationships between the ground-state energy and five critical parameters — the electron–phonon coupling strength, the vibration frequency, the magnetic field cyclotron resonance frequency, the transverse confinement length, and the longitudinal confinement length — are analyzed individually. The ground-state energy is an increasing function of the magnetic field cyclotron resonance frequency, while it is a decreasing function of the electron–phonon coupling strength, the vibration frequency, the transverse confinement length, and the longitudinal confinement length.