Far-infrared absorption in triangular and square quantum dots: Characterization of corner and side modes

Valín-Rodríguez, Manuel; Puente, A.; Serra, Llorenç

doi:10.1103/physrevb.64.205307

Cited by 11 publications

(13 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[3][4][5][6][7] This is due to the generalized Kohn's theorem, 8,9 stating that FIR couples only to the center-ofmass ͑c.m.͒ motion which in the case of a perfect parabolic potential can be separated from the relative motion. Since the c.m.…”

Section: Introductionmentioning

confidence: 97%

Electronic structure of rectangular quantum dots

et al. 2003

View full text Add to dashboard Cite

We study the ground state properties of rectangular quantum dots by using the spin-density-functional theory and quantum Monte Carlo methods. The dot geometry is determined by an infinite hard-wall potential to enable comparison to manufactured, rectangular-shaped quantum dots. We show that the electronic structure is very sensitive to the deformation, and at realistic sizes the non-interacting picture determines the general behavior. However, close to the degenerate points where Hund's rule applies, we find spin-density-wave-like solutions bracketing the partially polarized states. In the quasi-one-dimensional limit we find permanent charge-density waves, and at a sufficiently large deformation or low density, there are strongly localized stable states with a broken spin-symmetry.Comment: 8 pages, 9 figures, submitted to PR

show abstract

Section: Introductionmentioning

confidence: 97%

Electronic structure of rectangular quantum dots

et al. 2003

View full text Add to dashboard Cite

show abstract

“…34 The NF method 22 allowed the identification of the corner and the side modes of the infrared spectra in triangular and square two-dimensional QDs which could be modified by a vertical magnetic field. 35 Preliminary calculations for a single QD, neglecting the Coulomb interaction, FIG. 1.…”

Section: Introductionmentioning

confidence: 99%

“…revealed interesting modifications of the absorption spectra under perpendicular magnetic field. 36 In the works cited above, [32][33][34][35][36] B was applied in a characteristic perpendicular direction. Our computational scheme allows us to study QD structures of any given geometry, under a magnetic field of any orientation.…”

Section: Introductionmentioning

confidence: 99%

Near-field magnetoabsorption of quantum dots

2006

View full text Add to dashboard Cite

We investigate the effect of an external magnetic field of variable orientation and magnitude ͑up to 20 T͒ on the linear near-field optical absorption spectra of single and coupled III-V semiconductor quantum dots. We focus on the spatial as well as on the magnetic confinement, varying the dimensions of the quantum dots and the magnetic field. We show that the ground-state exciton binding energy can be manipulated utilizing the spatial and magnetic confinement. The effect of the magnetic field on the absorption spectra, increasing the near-field illumination spot, is also investigated. The zero-magnetic-field "structural" symmetry can be destroyed varying the magnetic field orientation and this affects the near-field spectra. The asymmetry induced ͑except for specific orientations along symmetry axes͒ by the magnetic field can be revealed in the near-field but not in the far-field spectra. We predict that near-field magnetoabsorption experiments, of realistic spatial resolution, will be in the position to bring to light the quantum dot symmetry. This exceptional symmetryresolving power of the near-field magnetoabsorption is lost in the far field. The influence of the Coulomb interactions on the absorption spectra is also discussed. Finally, we show that certain modifications of the magnetoexcitonic structure can be uncovered using a realistically acute near-field probe of Ϸ20 nm.

show abstract

“…Specifically, spatial resolution of 30 nm ( 30 l ª / , 930 l = nm) in the photoluminescence imaging of self-assembled InAs QDs [3] and successful real-space mapping of the center-of-mass wavefunctions of an exciton confined in a naturally occurring GaAs QD [4] were achieved. Furthermore, it has theoretically been predicted [5] that the local absorption method [1] allows the identification of the corner and the side modes of the infrared spectra in triangular and square two-dimensional QDs. These 2D spectra could be modified by a vertical magnetic field of varying intensity [5].…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, it has theoretically been predicted [5] that the local absorption method [1] allows the identification of the corner and the side modes of the infrared spectra in triangular and square two-dimensional QDs. These 2D spectra could be modified by a vertical magnetic field of varying intensity [5].…”

Section: Introductionmentioning

confidence: 99%