Intense terahertz laser field induced electro-magneto-donor impurity associated photoionization cross-section in Gaussian quantum wires
Abstract
Using expressions derived within the compact density matrix approach, the peaks of optical absorption and the
changes of refractive index of a hydrogenic impurity in a GaAs/GaAlAs Gaussian quantum well wire are
calculated taking into account the influence of static electric, magnetic and intense laser fields. The photoionization
cross section, with normalized photon energy, is computed for different values of static electric field,
magnetic field, and laser dressing parameter. The dipole moment matrix elements and the transition energy
between ground and first excited state energy levels are computed as functions of quantum wire width and
confinement potential depth, with and without external perturbations. Donor impurity binding energy is
investigated in presence of the aforementioned electromagnetic probes, using parabolic band and effective mass
approximations. The results show that the absorption coefficients depend on the transition energy difference
between initial and final states involved as well as on the corresponding polarization response via dipole matrix
elements. Discussed optical properties are field-sensitive and they can be tuned within the desired energy ranges
using these external perturbations.