Electrical instability of donor states in elongated quantum ring induced by external fields

摘要: Abstract The energy spectrum, dipole momentum, and polarizability induced by an off-axis donor in InAs/GaAs elongated volcano-shaped quantum dot the presence of external electric magnetic fields are theoretically investigated. Our calculations, carried out using adiabatic approximation Kane model, which takes into account effect non-parabolicity conduction band, show that estimated energies essentially lower than corresponding values obtained means effective mass approximation. mixing donor's energies, variation moment, charge distribution consistently described with our simple formalism, potential is related directly to morphology ring. In this structure, density two lowest “bonding” “anti-bonding” states tends align along one symmetry axes. donor-electron Coulomb attraction leads increase gap between these provides a strong polarization anti-bonding state. out-of-plane field decreases overlapping wave functions, while in-plane increases their reordering levels. We have found dependency on conditions displays phase transition state giant moment.