Energy levels of a quantum ring in a lateral electric field

The electronic states of a semiconductor quantum ring (QR) under an applied lateral electric field are theoretically investigated and compared with those of a quantum disk of the same size. The eigenstates and eigenvalues of the Hamiltonian are obtained from a direct matrix diagonalization scheme. Numerical calculations are performed for a hard-wall confinement potential and the electronic states are obtained as a function of the electric field and the ratio r₂/r₁, where r₂ (r₁) is the outer (inner) radius of the ring. The effects of decreasing symmetry and mixing on the energy levels and wave functions due to the applied electric field are also studied. The direct optical absorption are reported as a function of the electric field.