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Interpretation of experiments on quantum dot (QD) lasers presents a challenge: the phonon bottleneck, which should strongly suppress relaxation and dephasing of the discrete energy states, often seems to be inoperative. We suggest and…

Condensed Matter · Physics 2009-10-31 A. V. Uskov , A. -P. Jauho , B. Tromborg , J. Mork , R. Lang

We present full atomistic calculations of the spin-flip time (T$_{1}$) of electrons and holes mediated by acoustic phonons in self-assembled In$_{1-x}$Ga$_x$As/GaAs quantum dots at zero magnetic field. At low magnetic field, the first-order…

Materials Science · Physics 2015-05-20 Hai Wei , Ming Gong , G-C Guo , Lixin He

We investigate theoretically spin relaxation in heavy hole quantum dots in low external magnetic fields. We demonstrate that two-phonon processes and spin-orbit interaction are experimentally relevant and provide an explanation for the…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 Mircea Trif , Pascal Simon , Daniel Loss

We study theoretically phonon-assisted relaxation processes in a system consisting of one or two electrons confined in two vertically stacked self-assembled quantum dots. The calculation is based on a k.p approximation for single particle…

Mesoscale and Nanoscale Physics · Physics 2010-09-14 Krzysztof Gawarecki , Michał Pochwała , Anna Grodecka-Grad , Paweł Machnikowski

We study the relaxation dynamics of the electron system in graphene flakes under Landau quantization regime using a novel approach of time-resolved Raman scattering. The non-resonant character of the experiment allows us to analyze the…

The spin relaxation time $T_{1}$ in zinc blende GaN quantum dot is investigated for different magnetic field, well width and quantum dot diameter. The spin relaxation caused by the two most important spin relaxation mechanisms in zinc…

Materials Science · Physics 2009-04-11 M. Q. Weng , Y. Y. Wang , M. W. Wu

The relaxation time of a single-electron spin is an important parameter for solid-state spin qubits, as it directly limits the lifetime of the encoded information. Thanks to the low spin-orbit interaction and low hyperfine coupling,…

Mesoscale and Nanoscale Physics · Physics 2022-06-29 L. Banszerus , K. Hecker , S. Möller , E. Icking , K. Watanabe , T. Taniguchi , C. Volk , C. Stampfer

On the basis of first-principles calculations and the special displacement method, we demonstrate the quantum confinement scaling law of the phonon-induced gap renormalization of graphene quantum dots (GQDs). We employ zigzag-edged GQDs…

Materials Science · Physics 2021-10-19 Marios Zacharias , Pantelis C. Kelires

We have investigated spin relaxation times in CdTe quantum dots doped with a single Mn atom, a prototype of a system where the interaction between a single charge carrier and a single spin takes place. A theoretical model that was used…

Mesoscale and Nanoscale Physics · Physics 2015-06-03 Marko D. Petrović , Nenad Vukmirović

We calculate spin relaxation rates in lateral quantum dot systems due to electron exchange between dots and leads. Using rate equations, we develop a theoretical description of the experimentally observed electric current in the spin…

Mesoscale and Nanoscale Physics · Physics 2008-12-08 A. B. Vorontsov , M. G. Vavilov

We present a numerical study of spin relaxation in a semiclassical electron ensemble in a large ballistic quantum dot. The dot is defined in a GaAs/AlGaAs heterojunction system with a two-dimensional electron gas, and relaxation occurs due…

Mesoscale and Nanoscale Physics · Physics 2008-04-21 E. J. Koop , B. J. van Wees , C. H. van der Wal

We study decoherence of an electron spin qubit in a quantum dot due to charge noise. We find that at the lowest order, the pure dephasing channel is suppressed for both $1/f$ charge noise and Johnson noise, so that charge noise leads to a…

Mesoscale and Nanoscale Physics · Physics 2014-05-23 Peihao Huang , Xuedong Hu

We expand on previous work that treats relaxation physics of low-lying excited states in ideal, single electron, silicon quantum dots in the context of quantum computing. These states are of three types: orbital, valley, and spin. The…

Mesoscale and Nanoscale Physics · Physics 2014-02-12 Charles Tahan , Robert Joynt

Phonon-assisted singlet-singlet relaxation in semiconductor quantum dot molecules is studied theoretically. Laterally coupled quantum dot structures doped with two electrons are considered. We take into account interaction with acoustic…

Mesoscale and Nanoscale Physics · Physics 2009-04-27 A. Grodecka , P. Machnikowski , J. Förstner

Electrons in graphene are theoretically expected to retain spin states much longer than most materials, making graphene a promising platform for spintronics and quantum information technologies. Here, we use first-principles density-matrix…

Materials Science · Physics 2022-03-17 Adela Habib , Junqing Xu , Yuan Ping , Ravishankar Sundararaman

We analyzed theoretically localized charge relaxation in a double quantum dot (QD) system coupled with continuous spectrum states in the presence of localized electrons Coulomb interaction in a single QD. We have found that for a wide range…

Mesoscale and Nanoscale Physics · Physics 2012-07-13 V. N. Mantsevich , N. S. Maslova , P. I. Arseyev

Analysis of an exactly soluble model of phonons coupled to a carrier in a quantum dot provides a clear illustration of a phonon bottleneck to relaxation. The introduction of three-phonon interactions leads to a broad window for relaxation…

Condensed Matter · Physics 2007-05-23 S. A. Levetas , M. J. Godfrey , P. Dawson

We study the spin relaxation in a single-electron bilayer graphene quantum dot due to the spin-orbit coupling. The spin relaxation is assisted by the emission of acoustic phonons via the bond-length change and deformation potential…

Mesoscale and Nanoscale Physics · Physics 2025-05-21 Lin Wang , Guido Burkard

Graphene quantum dots (GQDs) can exhibit a range of spectacular phenomena such as the Klein-tunneling-induced quasibound states1-6 and Berry-phase-tuned energy spectra7-15. According to previous studies, all these interesting quantum…

Mesoscale and Nanoscale Physics · Physics 2024-03-08 Hui-Ying Ren , Ya-Ning Ren , Qi Zheng , Jia-Qi He , Lin He

In this paper we study the low temperature kinetics of the electrons in the system composed of a quantum dot connected to two leads by solving the equation of motion. The decoherence and the relaxation of the system caused by the gate…

Strongly Correlated Electrons · Physics 2009-11-13 M. Q. Weng