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We investigate the effects of the shape of quantum dots on their far-infrared absorption in an external magnetic field by a model calculation. We focus our attention on dots with a parabolic confinement potential deviating from the common…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Ingibjorg Magnusdottir , Vidar Gudmundsson

The optical absorption of a single spherical semiconductor quantum dot in an electrical field is studied taking into account the nonlocal coupling between the field of the light and the polarizability of the semiconductor. These nonlocal…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 F. Thiele , Ch. Fuchs , R. v. Baltz

We study the optical absorption of arrays of quantum dots and antidots in a perpendicular homogeneous magnetic field. The electronic system is described quantum mechanically using a Hartree approximation for the mutual Coulomb interaction…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Vidar Gudmundsson , Ingibjorg Magnusdottir , Sigurdur I. Erlingsson

Recent photoabsorption measurements have revealed a rich fine structure in the collective charge-density excitation spectrum of few-electron quantum dots in the presence of magnetic fields. We have performed systematic computational studies…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 C. A. Ullrich , G. Vignale

We investigate the relevance of the spin-orit coupling to the far-infrared absorption of two-dimensional semiconductor dots. Varying the strength of the Dresselhaus term, a mechanism feasible in experiment by changing the dot width,…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Manuel Valin-Rodriguez , Antonio Puente , Llorens Serra

A resonance behaviour of the far infrared absorption probability at a frequency \sim N^{1/4} is predicted for clusters of N electron-hole pairs (2\le N\le 110) confined in disk-shaped quantum dots. For radially symmetric dots, the…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Alain Delgado , Lester Lavin , Roberto Capote , Augusto Gonzalez

We investigate theoretically the spatial dependence of the linear absorption spectra of single and coupled semiconductor quantum dots, where the strong three-dimensional quantum confinement leads to an overall enhancement of Coulomb…

Materials Science · Physics 2009-10-31 C. Simserides , U. Hohenester , G. Goldoni , E. Molinari

The electronic continuum states of InAs/GaAs semiconductor quantum dots embedded in a GaAs/AlAs superlattice are theoretically investigated and the far infrared absorption spectra are calculated for a variety of structures and…

Other Condensed Matter · Physics 2009-11-11 Duc Phuong Nguyen , Nicolas Regnault , Robson Ferreira , Gerald Bastard

We investigate the far-infrared (FIR) absorption of a two-dimensional electron gas in a periodically modulated quantizing magnetic field. The magnetic field varies along only one spatial direction and the external time-dependent electric…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 Andrei Manolescu , Vidar Gudmundsson

Interband absorption and luminescence of quasi-two-dimensional, circularly symmetric, N_e electron quantum dots are studied at high magnetic fields, 8<B<60 T, and low temperatures, T<<2 K. In the N_e=0 and 1 dots, the initial and final…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Augusto Gonzalez , Eduardo Menendez-Proupin

Spin-orbit interaction in a quantum dot couples far infrared radiation to non center of mass excitation modes, even for parabolic confinement and dipole approximation. The intensities of the absorption peaks satisfy the optical sum rule,…

Strongly Correlated Electrons · Physics 2015-06-25 P. Lucignano , B. Jouault , A. Tagliacozzo

Here we embark on a thorough investigation of the magneto-optical absorption in semiconducting {\em spherical} quantum dots characterized by a confining harmonic potential and an applied magnetic field in the symmetric gauge. This is done…

Mesoscale and Nanoscale Physics · Physics 2016-04-13 Manvir S. Kushwaha

We generalize the Kohn's theorem to the case of parabolic three-dimensional quantum dots in magnetic fields of arbitrary direction. We show numerically that the exact resonance frequencies in the magneto-optical absorption of these dots are…

Condensed Matter · Physics 2007-05-23 Marti Pi , Francesco Ancilotto , Enrico Lipparini

We study numerically the optical properties of low-buckled silicene and AB-stacked bilayer graphene quantum dots subjected to an external electric field, which is normal to their surface. Within the tight-binding model, the optical…

Mesoscale and Nanoscale Physics · Physics 2017-08-29 H. Abdelsalam , M. H. Talaat , I. Lukyanchuk , M. E. Portnoi , V. A. Saroka

We report a theoretical description of far-infrared spectroscopy experiments on self-assembled quantum rings in a magnetic field [A. Lorke et al., Phys. Rev. Lett. 84, 2223 (2000)] which, for the first time, accounts for the full set of…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Josep Planelles , Juan I. Climente

A theoretical description of local absorption is proposed in order to investigate spectral variations on a length scale comparable with the extension of the relevant quantum states. A general formulation is derived within the density-matrix…

Materials Science · Physics 2009-10-31 O. Mauritz , G. Goldoni , F. Rossi , E. Molinari

Electromagnetic characteristics of single-walled finite-length carbon nanotubes - absorption cross-section and field enhancement in the near zone - are theoretically studied in a wide frequency range from terahertz to visible. The analysis…

Materials Science · Physics 2008-06-19 M. V. Shuba , S. A. Maksimenko , G. Ya. Slepyan

Within the framework of adiabatic approximation, the energy levels and direct interband light absorption in a strongly prolated ellipsoidal quantum dot are studied. Analytical expressions for the particle energy spectrum and absorption…

Mesoscale and Nanoscale Physics · Physics 2015-05-08 K. G. Dvoyan , D. B. Hayrapetyan , E. M. Kazaryan

We have investigated the far-infrared dipole modes of a quantum antidot submitted to a perpendicularly applied magnetic field B. The ground state of the antidot is described within local spin-density functional theory, and the spectrum…

Condensed Matter · Physics 2009-10-31 A. Emperador , M. Pi , M. Barranco , E. Lipparini , Ll. Serra

Recently developed eigenvalue method is being used to calculate absorption spectra in magnetic square nanodots and nanodisks. Obtained results are being compared with both theoretical and experimental results obtained previously for such…

Materials Science · Physics 2007-05-23 K. Rivkin , Lance DeLong , John B. Ketterson
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