Binding energy of impurity states in a parabolic quantum dot in a strong magnetic field

Abstract

The binding energies of shallow hydrogenic impurities in parabolic quantum dots are calculated using a variational approach within the effective mass approximation. Results are obtained for Cd 1-x in Mn x in Te/Cd 1-x out Mn x out Te structures as a function of the dot radius in an external magnetic field. The results show that the impurity binding energy (i) increases with the decrease in dot radius, (ii) decreases when the magnetic field is increased for a given dot and (iii) increases to a maximum value at 90 Å and then decreases as the size of the dot increases beyond 90 Å in the finite barrier case. This feature is different from non magnetic quantum well structures. Spin polaronic shifts are estimated using a mean field theory. The results show that the shifts are ≤1 meV in the zero-field case and still smaller in a magnetic field. This shift not only decreases in a magnetic field but also decreases when the dot radius increases.

Effect of s – d Exchange with an Itinerant Carrier in a GaMnAs/Ga0.4 Al0.6 As Quantum Dot: Effects of Magnetic Field and Spatial Confinement

“…In general, in all low dimensional heterostructures, the magnetic field increases with the binding energy. 21 The insert figure brings out the effect of applied magnetic field on the hydrogenic donor impurity. The donor diamagnetic shift as a function of magnetic field for the GaMnAs/Ga 0 4 Al 0 6 As quantum dot is shown here.…”

Effects of Hydrostatic Pressure on Optical Absorption and Refractive Index Changes of Exciton in Semimagnetic CdMnTe Quantum Wells

“…The variation of band gap differences is taken from the Ref. [16] and the strain-induced potential for the conduction band in the influence of pressure is given by 17 V C strian P = a c xx P + yy P + zz P (6) where a c is the deformation potential constant of conduction band, xx P = yy P = a 0 P − a P /a P where a 0 P and a P are the pressure dependent lattice parameters of bulk CdTe (6.481 nm) and MnTe (6.334 nm) respectively and zz P = −2C 12 P /C 11 P xx P , the values of parameters C 11 and C 12 are 5 66 + 0 36 GPa and 3 96 + 0 44 GPa. 18 19 The strain-induced potential for the valence band in the influence of pressure can be written as 20…”

Calculation of Zeeman splitting and Zeeman transition energies of spherical quantum dot in uniform magnetic field

“…Peter et al [35] and Wu and Wan [37] investigated the electronic structure and binding energies of parabolic and spherical QDs in a strong external magnetic field by using variational approach. Zhang et al [40] and Seddik et al [42] studied the field effects on the optical properties in parabolic QDs in the presence of electric and magnetic fields.…”

“…The symmetry of the impurity states, the nature of the wave functions leading to more complicated changes of the binding energy and the other properties of impurity energy states can be modified by application of a magnetic field to QDs. Therefore, several studies [33][34][35][36][37][38][39][40][41][42][43][44][45][46] are performed on the electronic structures, energy states, binding energies, optical and other properties of QDs in the presence of a magnetic field.…”