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Related papers: Suppression of exciton dephasing in quantum dots t…

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We study the phonon-induced dephasing of the exciton state in a quantum dot excited by a sequence of ultra-short pulses. We show that the multiple-pulse control leads to a considerable improvement of the coherence of the optically excited…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 V. M. Axt , P. Machnikowski , T. Kuhn

Semiconductor quantum dots are excellent candidates for ultrafast coherent manipulation of qubits by laser pulses on picosecond timescales or even faster. In inhomogeneous ensembles a macroscopic optical polarization decays rapidly due to…

Mesoscale and Nanoscale Physics · Physics 2020-06-11 A. N. Kosarev , H. Rose , S. V. Poltavtsev , M. Reichelt , C. Schneider , M. Kamp , S. Hoefling , M. Bayer , T. Meier , I. A. Akimov

We investigate the effectiveness of different dynamical decoupling protocols for storage of a single qubit in the presence of a purely dephasing bosonic bath, with emphasis on comparing quantum coherence preservation under uniform vs.…

Quantum Physics · Physics 2015-05-14 Thomas E. Hodgson , Lorenza Viola , Irene D'Amico

We address the experimentally relevant problem of robust mitigation of dephasing noise acting on a qubit. We first present an extension of a method for representing $1/\omega^{\alpha}$ noise developed by Kuopanportti et al. to the efficient…

Quantum Physics · Physics 2010-06-01 Kevin C. Young , Dylan J Gorman , K. Birgitta Whaley

We study the evolution of an exciton confined in a quantum dot adiabatically controlled by a frequency-swept (chirped) laser pulse in the presence of carrier-phonon coupling. We focus on the dynamics induced by a linearly polarized beam and…

Mesoscale and Nanoscale Physics · Physics 2013-01-16 K. Gawarecki , S. Lüker , D. E. Reiter , T. Kuhn , M. Glässl , V. M. Axt , A. Grodecka-Grad , P. Machnikowski

Optical techniques for the quantum control of the dynamics of multiexciton states in a semiconductor quantum dot are explored in theory. Composite bichromatic phase-locked pulses are shown to reduce the time of elementary quantum operations…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 C. Piermarocchi , Pochung Chen , Y. S. Dale , L. J. Sham

We study phonon-assisted dephasing in optically excited semiconductor quantum dots within the frameworks of the independent Boson model and optimal control. Using a realistic description for the quantum dot states and the phonon coupling,…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Ulrich Hohenester

Reducing decoherence is an essential step toward realizing general-purpose quantum computers beyond the present noisy intermediate-scale quantum (NISQ) computers. To this end, dynamical decoupling (DD) approaches in which external fields…

Quantum Physics · Physics 2022-09-23 Yukiyoshi Ohtsuki , Suicho Mikami , Toru Ajiki , David J. Tannor

Dephasing is a ubiquitous phenomenon that leads to the loss of coherence in quantum systems and the corruption of quantum information. We present a universal dynamical control approach to combat dephasing during all stages of quantum…

Quantum Physics · Physics 2009-11-13 Goren Gordon , Gershon Kurizki

We consider a class of multi-qubit dephasing models that combine classical noise sources and linear coupling to a bosonic environment, and are controlled by arbitrary sequences of dynamical decoupling pulses. Building on a general transfer…

Quantum Physics · Physics 2016-08-03 Gerardo A. Paz-Silva , Seung-Woo Lee , Todd J. Green , Lorenza Viola

We provide a self-contained review of master equation approaches to modelling phonon effects in optically driven self-assembled quantum dots. Coupling of the (quasi) two-level excitonic system to phonons leads to dissipation and dephasing,…

Mesoscale and Nanoscale Physics · Physics 2016-06-14 Ahsan Nazir , Dara P. S. McCutcheon

Currently available quantum computers are prone to errors. Circuit optimization and error mitigation methods are needed to design quantum circuits to achieve better fidelity when executed on NISQ hardware. Dynamical decoupling (DD) is…

Quantum Physics · Physics 2022-09-05 Siyuan Niu , Aida Todri-Sanial

A central task towards building a practical quantum computer is to protect individual qubits from decoherence while retaining the ability to perform high-fidelity entangling gates involving arbitrary two qubits. Here we propose and…

Over the past decade we have seen an explosion of demonstrations of quantum coherence in atomic, optical, and condensed matter systems. These developments have placed a new emphasis on the production of robust and optimal quantum control…

Quantum Physics · Physics 2015-05-20 M. J. Biercuk , A. C. Doherty , H. Uys

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

Dynamical decoupling pulse sequences have been used to extend coherence times in quantum systems ever since the discovery of the spin-echo effect. Here we introduce a method of recursively concatenated dynamical decoupling pulses, designed…

Quantum Physics · Physics 2007-05-23 K. Khodjasteh , D. A. Lidar

Quantum computers, which process information encoded in quantum mechanical systems, hold the potential to solve some of the hardest computational problems. A substantial obstacle for the further development of quantum computers is the fact…

Quantum Physics · Physics 2012-11-02 Alexandre M. Souza , Gonzalo A. Álvarez , Dieter Suter

The phonon-induced dephasing dynamics in optically excited semiconductor quantum dots is studied within the frameworks of the independent Boson model and optimal control. We show that appropriate tailoring of laser pulses allows a complete…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Ulrich Hohenester , Georg Stadler

We study the dissipative dynamics of a qubit that is afflicted by classical random telegraph noise and it is subject to dynamical decoupling. We derive exact formulas for the qubit dynamics at arbitrary working points in the limit of…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 Joakim Bergli , Lara Faoro

We investigate the performance of dynamical decoupling methods at suppressing electron spin decoherence from a low-temperature nuclear spin reservoir in a quantum dot. The controlled dynamics is studied through exact numerical simulation,…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Wenxian Zhang , V. V. Dobrovitski , Lea F. Santos , Lorenza Viola , B. N. Harmon
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