Effect of an intense laser field on donor impurities in spherical quantum dots

doi:10.1006/spmi.2001.0992

Superlattices and Microstructures

Volume 30, Issue 1, July 2001, Pages 45-52

https://doi.org/10.1006/spmi.2001.0992 Get rights and content

Abstract

The effect of an intense laser field on the binding energy of hydrogenic impurity states with an impurity atom located at the center of a spherical quantum dot confined by an infinite barrier potential are studied as a function of the dot radius and of the intensity and frequency of the laser field. Accurate binding energies are obtained for the 1s, 2s and 2p states by numerical integration of the Schrödinger equation. The binding energies are found to increase with decrease in the dot radius, and decrease with increase in the value of the laser field amplitude λ in all cases.

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Citation Excerpt :
Such differences and the alternativeness of the external electric and magnetic field, due to its time-dependent and high-frequency, make rigorous theoretical investigations with the ILF stand out when compared to ones in other fields. The effect of the ILF on donor impurities of a spherical QD confined by infinity barrier potential has been viewed using the numerical integration Schrödinger equation [24]. The optical RICs and ACs [25], the second and third harmonics generation characteristics [26], and the nonlinear optical rectification characteristics [27] are some of the important theoretical research subjects that consider effects of the ILF.
In this study, the influence of the external electric field on the nonlinear optical properties of a laser dressed cylindrical quantum dot with axial Morse potential are theoretically investigated using the total optical absorption coefficient as well as relative refractive index changes. The effect of the structural parameters on the structure's intraband optical properties is analyzed, optimizing the quantum dot in terms of the total optical absorption coefficient and the relative refractive index. Single-electron energies and wave functions of the system have been determined using analytical methods and the exact diagonalization technique. The quantities above mentioned are examined with the compact-density-matrix approach. The obtained results demonstrated that the system's intraband optical properties closely depend on both the applied external fields and the structural parameters. Such adequate tuning of the laser-dressed cylindrical quantum dots’ intraband optical properties gives us new possibilities in the regions of interest for optoelectronic device applications.
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Combined effect of magnetic and the intense laser fields on the donor-bound magnetic polaron of semi-magnetic core shell nanostructures is investigated theoretically to explore them for opto-electronic, spintronic devices. Based on the band alignments of donor, the two probable semi-magnetic Core Shell Nanostructures (CSNs) namely type I CdTe/Cd_0.7Mn_0.3Te and reverse type I Cd_0.7Mn_0.3Te/CdTe are considered in the present study. The interplay of Bound Magnetic Polaron (BMP) with the donor impurity is explored through spin polaronic energy (E_SP) and magnetization (M) for different laser and magnetic fields by applying laser field intensity ranging from 0.58 to 14.5 μW/Å² of frequency 10 THz along with magnetic field (B) of about 5–30 T. The dimensional impact of dot and the barrier of the respective CSN on the sublevel Energy (SE), E_SP and M is also examined under applied external fields. The carriers of reverse type I CSN are more dynamic and perform diverse behaviour in the presence of external laser and magnetic fields.
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Effect of an intense laser field on donor impurities in spherical quantum dots