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Related papers: Large quantum dots with small oscillator strength

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We report the realization of a hybrid superconductor-quantum dot device by means of top-down nanofabrication starting from a two dimensional electron gas in a InGaAs/InAlAs semiconductor heterostructure. The quantum dot is defined by…

Mesoscale and Nanoscale Physics · Physics 2011-04-15 Fabio Deon , Vittorio Pellegrini , Francesco Giazotto , Giorgio Biasiol , Lucia Sorba , Fabio Beltram

Excitonic states and the line shape of optical transitions in coupled quantum dots (quantum dot molecules) are studied theoretically. For a pair of electrically tunable, vertically aligned quantum dots we investigate the coupling between…

Mesoscale and Nanoscale Physics · Physics 2013-11-22 J. M. Daniels , P. Machnikowski , T. Kuhn

We study the quantum oscillations of inter-layer capacitance in an excitonic insulating electron-hole double layer with the Hartree Fock mean-field theory. Such oscillations could be simply understood from the physical picture ``exciton…

Strongly Correlated Electrons · Physics 2024-04-03 Yuelin Shao , Xi Dai

Semiconductor quantum dots coherently driven by pulsed laser are fundamental physical systems which allow studying the dynamical properties of confined quantum states. These systems are attractive candidates for a solid-state qubit, which…

Mesoscale and Nanoscale Physics · Physics 2010-03-22 H. S. Borges , L. Sanz , J. M. Villas-Boas , A. M. Alcalde

A single-electron transistor has been realized in a Ga[Al]As heterostructure by oxidizing lines in the GaAs cap layer with an atomic force microscope. The oxide lines define the boundaries of the quantum dot, the in-plane gate electrodes,…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 S. Luescher , A. Fuhrer , R. Held , T. Heinzel , K. Ensslin , W. Wegscheider

Two strongly coupled quantum dots are theoretically and experimentally investigated. In the conductance measurements of a GaAs based low-dimensional system additional features to the Coulomb blockade have been detected at low temperatures.…

Mesoscale and Nanoscale Physics · Physics 2008-09-23 F. J. Kaiser , S. Kohler , P. Hänggi , M. Malecha , J. Ebbecke , A. Wixforth , H. W. Schumacher , B. Kästner , D. Reuter , A. D. Wieck

We use single self-assembled InGaAs quantum dots as internal probes to map the local density of optical states of photonic crystal membranes. The employed technique separates contributions from non-radiative recombination and spin-flip…

Quantum Physics · Physics 2015-05-28 Qin Wang , Søren Stobbe , Peter Lodahl

The binding energy and the corresponding wave function of excitons in GaAs-based finite square quantum wells (QWs) are calculated by the direct numerical solution of the three-dimensional Schroedinger equation. The precise results for the…

Quantum dots play a promising role in the development of novel optical and biosensing devices. In this study, we investigated steady-state and time-dependent luminescence properties of InGaP/ZnS core/shell colloidal quantum dots in a…

Materials Science · Physics 2012-07-30 Subhasish Chatterjee , Nikesh V. Valappil , Vinod M. Menon

We theoretically study the coupled modes of a medium-size quantum dot, which may confine a maximum of ten electron-hole pairs, and a single photonic mode of an optical microcavity. Ground-state and excitation energies, exciton-photon mixing…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Herbert Vinck , Boris A. Rodriguez , Augusto Gonzalez

We employ dynamical density-matrix renormalization group (DDMRG) and field-theory methods to determine the frequency-dependent optical conductivity in one-dimensional extended, half-filled Hubbard models. The field-theory approach is…

Strongly Correlated Electrons · Physics 2009-11-07 F. H. L. Essler , F. Gebhard , E. Jeckelmann

We demonstrate charge tuning in strain free GaAs/AlGaAs quantum dots (QDs) grown by droplet epitaxy on a GaAs(111)A substrate. Application of a bias voltage allows the controlled charging of the QDs from $-3|e|$ to $+2|e|$. The resulting…

Mesoscale and Nanoscale Physics · Physics 2014-08-29 L. Bouet , M. Vidal , T. Mano , N. Ha , T. Kuroda , M. V. Durnev , M. M. Glazov , E. L. Ivchenko , X. Marie , T. Amand , K. Sakoda , G. Wang , B. Urbaszek

Using far-infrared spectroscopy, we investigate the excitations of self-organized InAs quantum dots as a function of the electron number per dot, 1<n<6, which is monitored in situ by capacitance spectroscopy. Whereas the well-known two-mode…

Condensed Matter · Physics 2009-10-28 M. Fricke , A. Lorke , J. P. Kotthaus , G. Medeiros-Ribeiro , P. M. Petroff

Excitons are spin integer particles that are predicted to condense into a coherent quantum state at sufficiently low temperature, and exciton condensates can be realized at much higher temperature than condensates of atoms because of strong…

We demonstrate sub-wavelength imaging of excitons confined to single CdTe quantum dots. By combining slit-confocal microscopy with a hemispherical solid immersion lens we simultaneously map the emission of thousands of single quantum dots…

Other Condensed Matter · Physics 2009-11-10 K. P. Hewaparakrama , S. Mackowski , H. E. Jackson , L. M. Smith , G. Karczewski , J. Kossut

Excitons, which represent a type of quasi-particles consisting of electron-hole pairs bound by the mutual Coulomb interaction, were often observed in lowly-doped semiconductors or insulators. However, realizing excitons in the…

The demonstration of degeneracy of the exciton spin states is an important step towards the production of entangled photons pairs from the biexciton cascade. We measure the fine structure of exciton and biexciton states for a large number…

Multi-electron semiconductor quantum dots have found wide application in qubits, where they enable readout and enhance polarizability. However, coherent control in such dots has typically been restricted to only the lowest two levels, and…

We present graphene quantum dots endowed with addition energies as large as 1.6 eV, fabricated by the controlled rupture of a graphene sheet subjected to a large electron current in air. The size of the quantum dot islands is estimated to…

Mesoscale and Nanoscale Physics · Physics 2013-01-30 Amelia Barreiro , Herre S. J. van der Zant , Lieven M. K. Vandersypen

Emerging applications of self-assembled semiconductor quantum dot (QD)-based nonclassical light sources emitting in the telecom C-band (1530 to 1565 nm) present challenges in terms of controlled synthesis of their low-density ensembles,…

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