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We report on capacitance-voltage spectroscopy of self-assembled InAs quantum dots under constant illumination. Besides the electronic and excitonic charging peaks in the spectrum reported earlier, we find additional resonances associated…

Mesoscale and Nanoscale Physics · Physics 2018-01-24 Sascha R. Valentin , Jonathan Schwinger , Pia Eickelmann , Patrick A. Labud , Andreas D. Wieck , Björn Sothmann , Arne Ludwig

Quasi-static transport measurements are employed on a laterally defined tunnel-coupled double quantum dot. A nearby quantum point contact allows us to track the charge as added to the device. If charged with only up to one electron, the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 A. K. Huettel , S. Ludwig , K. Eberl , J. P. Kotthaus

Deterministic light sources capable of generating quantum states on-demand at wavelengths compatible with fiber optics and atmospheric transmission windows are essential for practical applications in quantum communication, distributed…

Excitonic spectra are calculated for free-standing, surface passivated InAs quantum dots using atomic pseudopotentials for the single-particle states and screened Coulomb interactions for the two-body terms. We present an analysis of the…

Materials Science · Physics 2009-10-31 A. J. Williamson , Alex Zunger

The energy levels and optical transitions of tetrahedral core/shell InP/ZnSe quantum dots (QDs) are investigated by means of multi-band k$\cdot$p theory. Despite the $\overline{T}_d$ symmetry relaxing spherical selection rules, the…

Mesoscale and Nanoscale Physics · Physics 2026-04-06 Josep Planelles , Juan I. Climente

We investigate site-controlled In$_{0.25}$Ga$_{0.75}$As quantum dots in (111)B GaAs pyramidal recesses as spin qubits. Combining scanning confocal cryomicroscopy, magneto-photoluminescence studies and resonant excitation, we identify and…

Mesoscale and Nanoscale Physics · Physics 2025-09-09 R. A. Barcan , I. Samaras , K. Barr , G. Juska , E. Pelucchi , K. G. Lagoudakis

We report the direct observation of coupling between a single self-assembled InAs quantum dot and a wetting layer, based on strong diamagnetic shifts of many-body exciton states using magneto-photoluminescence spectroscopy. An extremely…

We have demonstrated experimentally the manipulation of exciton and nuclear spins in a single self-assembled In$_{0.75}$Al$_{0.25}$As/Al$_{0.3}$Ga$_{0.7}$As quantum dot. The oscillation of exciton and nuclear spin polarizations were clearly…

Other Condensed Matter · Physics 2007-05-23 H. Sasakura , S. Adachi , S. Muto , S. Hirose , H. Z. Song , M. Takatsu

The exciton lifetimes $T_1$ in arrays of InAs/GaAs vertically coupled quantum dot pairs have been measured by time-resolved photoluminescence. A considerable reduction of $T_1$ by up to a factor of $\sim$ 2 has been observed as compared to…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 C. Bardot , M. Schwab , M. Bayer , S. Fafard , Z. Wasilewski , P. Hawrylak

We report on single InGaAs quantum dots embedded in a lateral electric field device. By applying a voltage we tune the neutral exciton transition into resonance with the biexciton using the quantum confined Stark effect. The results are…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 M. Kaniber , M. F. Huck , K. Müller , E. C. Clark , F. Troiani , M. Bichler , H. J. Krenner , J. J. Finley

We demonstrate experimental results based on time-resolved photoluminescence spectroscopy to determine the oscillator strength (OS) and the internal quantum efficiency (IQE) of InGaAs quantum dots (QDs). Using a strain-reducing layer (SRL)…

Applied Physics · Physics 2021-08-24 Jan Große , Pawel Mwrowinski , Nicole Srocka , Stephan Reitzenstein

In this work, we have investigated conduction through an artificial molecule comprising two coupled quantum dots. The question addressed is the role of inter-dot coupling on electronic transport. We find that the current through the…

Mesoscale and Nanoscale Physics · Physics 2011-09-22 M. Imran , B. Tariq , M. Tahir , K. Sabeeh

We demonstrate tuning of single quantum dot emission lines by the combined action of the dynamic acoustic field of a radio frequency surface acoustic wave and a static electric field. Both tuning parameters are set all-electrically in a…

Mesoscale and Nanoscale Physics · Physics 2015-01-09 J. Pustiowski , K. Müller , M. Bichler , G. Koblmüller , J. J. Finley , A. Wixforth , H. J. Krenner

Cathodoluminescence spectra employing a shadow mask technique of InGaN layers grown by metal organic chemical vapor deposition on Si(111) substrates are reported. Sharp lines originating from InGaN quantum dots are observed. Temperature…

Materials Science · Physics 2007-05-23 R. Seguin , S. Rodt , A. Strittmatter , L. Reißmann , T. Bartel , A. Hoffmann , D. Bimberg

Most self-assembled quantum dot molecules are intrinsically asymmetric with inequivalent dots resulting from imperfect control of crystal growth. We have grown vertically-aligned pairs of InAs/GaAs quantum dots by molecular beam epitaxy,…

The spin states of electrons and holes confined in InAs quantum dot molecules have recently come to fore as a promising system for the storage or manipulation of quantum information. We describe here a feasible scheme for complete quantum…

Mesoscale and Nanoscale Physics · Physics 2015-01-09 Guy Z. Cohen

In contrast to interband excitons in undoped quantum wells, doped quantum wells do not display sharp resonances due to excitonic bound states. In these systems the effective Coulomb interaction between electrons and holes typically only…

We measure the shot noise of a quantum point-contact using a capacitively coupled InAs double quantum dot as an on-chip sensor. Our measurement signals are the (bidirectional) interdot electronic tunneling rates which are determined by…

Mesoscale and Nanoscale Physics · Physics 2009-09-21 Bruno Küng , Simon Gustavsson , Theodore Choi , Ivan Shorubalko , Thomas Ihn , Silke Schön , Fabian Hassler , Gianni Blatter , Klaus Ensslin

We investigate the effect of an applied magnetic field on resonant tunneling of electrons through the bound states of self-assembled InAs quantum dots (QDs) embedded within an (AlGa)As tunnel barrier. At low temperatures (no more than 2 K),…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 E. E. Vdovin , Yu. N. Khanin , O. Makarovsky , A. Patane , L. Eaves , M. Henini , C. J. Mellor , K. A. Benedict , R. Airey

Doping a self-assembled InGaAs/GaAs quantum dot (QD) with a single Mn atom, a magnetic acceptor impurity, provides a quantum system with discrete energy levels and original spin-dependent optical selection rules, which thus has large…

Mesoscale and Nanoscale Physics · Physics 2024-10-28 Jovana Filipovic , Ankit Kundu , Neelesh Kumar Vij , Simon Fécherolle , Aristide Lemaître , Shilpi Gupta , Olivier Krebs