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The relaxation of electrons in quantum dots via phonon emission is hindered by the discrete nature of the dot levels (phonon bottleneck). In order to clarify the issue theoretically we consider a system of $N$ discrete fermionic states (dot…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 T. Stauber , R. Zimmermann , H. Castella

We find an interference effect for electron-phonon interactions in coupled semiconductor quantum dots that can dominate the nonlinear transport properties even for temperatures close to zero. The intradot electron tunnel process leads to a…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Tobias Brandes , Bernhard Kramer

We study the relaxation of the exciton spin (longitudinal relaxation time $T_{1}$) in single asymmetrical quantum dots due to an interplay of the short--range exchange interaction and acoustic phonon deformation. The calculated relaxation…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 E. Tsitsishvili , R. v. Baltz , H. Kalt

We present a detailed study of a phonon-assisted incoherent excitation mechanism of single quantum dots. A spectrally-detuned laser couples to a quantum dot transition by mediation of acoustic phonons, whereby excitation efficiencies up to…

Optics · Physics 2015-06-05 S. Weiler , A. Ulhaq , C. Roy , S. M. Ulrich , D. Richter , M. Jetter , S. Hughes , P. Michler

We study theoretically the phonon-induced relaxation ($T_1$) and decoherence times ($T_2$) of singlet-triplet qubits in lateral GaAs double quantum dots (DQDs). When the DQD is biased, Pauli exclusion enables strong dephasing via two-phonon…

Mesoscale and Nanoscale Physics · Physics 2014-02-17 Viktoriia Kornich , Christoph Kloeffel , Daniel Loss

A new microscopic approach to the optical transitions in quantum dots and quantum dot molecules, which accounts for both diagonal and non-diagonal exciton-phonon interaction, is developed. The cumulant expansion of the linear polarization…

Other Condensed Matter · Physics 2015-06-25 E. A. Muljarov , T. Takagahara , R. Zimmermann

We investigate the influence of the electron-phonon interaction on the decay dynamics of a quantum dot coupled to an optical microcavity. We show that the electron-phonon interaction has important consequences on the dynamics, especially…

Mesoscale and Nanoscale Physics · Physics 2012-08-17 P. Kaer , T. R. Nielsen , P. Lodahl , A. -P. Jauho , J. Mork

We study theoretically the phonon-induced relaxation and decoherence of spin states of two electrons in a lateral double quantum dot in a SiGe/Si/SiGe heterostructure. We consider two types of singlet-triplet spin qubits and calculate their…

Mesoscale and Nanoscale Physics · Physics 2018-05-29 Viktoriia Kornich , Christoph Kloeffel , Daniel Loss

We investigate the effect of vibrational degrees of freedom on the linear thermoelectric transport through a single-level quantum dot described by the spinless Anderson-Holstein impurity model. To study the effects of strong electron-phonon…

Strongly Correlated Electrons · Physics 2017-11-30 A. Khedri , V. Meden , T. A. Costi

An effective spin relaxation mechanism that leads to electron spin decoherence in a quantum dot is proposed. In contrast to the common calculations of spin-flip transitions between the Kramers doublets, we take into account a process of…

Materials Science · Physics 2009-11-10 Y. G. Semenov , K. W. Kim

An electron-phonon cavity consisting of a quantum dot embedded in a free-standing GaAs/AlGaAs membrane is characterized in Coulomb blockade measurements at low temperatures. We find a complete suppression of single electron tunneling around…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 E. M. Höhberger , R. H. Blick , T. Brandes , J. Kirschbaum , W. Wegscheider , M. Bichler , J. P. Kotthaus

The phonon-induced spin relaxation in a two-dimensional quantum dot embedded inside a semiconductor slab is investigated theoretically. An enhanced relaxation rate is found due to the phonon van Hove singularities. Oppositely, a vanishing…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Y. Y. Liao , Y. N. Chen , D. S. Chuu , T. Brandes

We estimate the triplet-singlet relaxation rate due to spin-orbit coupling assisted by phonon emission in weakly-confined quantum dots. Our results for two and four electrons show that the different triplet-singlet relaxation trends…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Juan I. Climente , Andrea Bertoni , Guido Goldoni , Massimo Rontani , Elisa Molinari

We probe acoustic phonon mediated relaxation between tunnel coupled exciton states in an individual quantum dot molecule in which the inter-dot quantum coupling and energy separation between exciton states is continuously tuned using static…

Mesoscale and Nanoscale Physics · Physics 2007-10-10 T. Nakaoka , H. J. Krenner , E. C. Clark , M. Sabathil , M. Bichler , Y. Arakawa , G. Abstreiter , J. J. Finley

We have theoretically studied phonon-mediated spin-flip processes of electrons in a GaAs double quantum dot (DQD) holding two spins, under a phonon temperature gradient over the DQD. Transition rates of inter-dot phonon-assisted tunnel…

Mesoscale and Nanoscale Physics · Physics 2026-05-22 Kazuyuki Kuroyama , Sadashige Matsuo , Seigo Tarucha , Yasuhiro Tokura

We theoretically study the $(1,1)$ triplet to $(0,2)$ singlet relaxation rate in a lateral gate-defined double quantum dot tuned to the regime of Pauli spin blockade. We present a detailed derivation of the effective phonon density of…

Mesoscale and Nanoscale Physics · Physics 2015-06-15 J. Danon

Optically active quantum dot molecules (QDMs) can host multi-spin quantum states with the potential for the deterministic generation of photonic graph states with tailored entanglement structures. Their usefulness for the generation of such…

Electron transport through a double quantum dot system is studied with taking into account electron-phonon interaction. The Keldysh nonequilibrium Green function formalism is used to compute the current and transmission coefficient of the…

Mesoscale and Nanoscale Physics · Physics 2012-04-11 M. Bagheri Tagani , H. Rahimpour Soleimani

We calculate the rates of phonon-assisted hyperfine spin flips during electron and hole tunneling between quantum dots in a self-assembled quantum dot molecule. We show that the hyperfine process dominates over the spin-orbit-induced spin…

Mesoscale and Nanoscale Physics · Physics 2021-07-28 Paweł Karwat , Krzysztof Gawarecki , Paweł Machnikowski

Here we present details on how the cooling effects of an opto-mechanical system are affected beyond the secular approximation. To this end, a laser driven two-level quantum dot (QD) embed- ded in a phononic nano-cavity is investigated for…

Quantum Physics · Physics 2018-03-16 Victor Ceban , Mihai A. Macovei