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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

Dynamical decoupling can be used to preserve arbitrary quantum states despite undesired interactions with the environment, using control Hamiltonians affecting the system only. We present a system-independent analysis of dynamical…

Quantum Physics · Physics 2009-11-13 Kaveh Khodjasteh , Daniel A. Lidar

Reliable long-time storage of arbitrary quantum states is a key element for quantum information processing. In order to dynamically decouple a spin or quantum bit from a dephasing environment, we introduce an optimized sequence of $N$…

Quantum Physics · Physics 2010-04-08 Götz S. Uhrig , Stefano Pasini

The loss of quantum information due to interaction with external degrees of freedom, which is known as decoherence, remains one of the main obstacles for large-scale implementations of quantum computing. Accordingly, different measures are…

Quantum Physics · Physics 2012-06-13 Gonzalo A. Alvarez , Alexandre M. Souza , Dieter Suter

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

Structured decompositions of a desired unitary operator are employed to derive control schemes that achieve certain control objectives for finite-level quantum systems using only sequences of simple control pulses such as square waves with…

Quantum Physics · Physics 2007-05-23 S. G. Schirmer , A. D. Greentree , V. Ramakrishna , H. Rabitz

An optimal dynamical decoupling of a quantum system coupled to a noisy environment must take into account also the imperfections of the control pulses. We present a new formalism which describes, in a closed-form expression, the evolution…

Quantum Physics · Physics 2016-10-19 Ido Almog , Gil Loewenthal , Jonathan Coslovsky , Yoav Sagi , Nir Davidson

We explore the physical limits of pulsed dynamical decoupling methods for decoherence control as determined by finite timing resources. By focusing on a decohering qubit controlled by arbitrary sequences of $\pi$-pulses, we establish a…

Quantum Physics · Physics 2011-04-11 Kaveh Khodjasteh , Tamás Erdélyi , Lorenza Viola

A dynamical decoupling method is presented which is based on embedding a deterministic decoupling scheme into a stochastic one. This way it is possible to combine the advantages of both methods and to increase the suppression of undesired…

Quantum Physics · Physics 2007-05-23 Oliver Kern , Gernot Alber

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

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

The aim of dynamical decoupling consists in the suppression of decoherence by appropriate coherent control of a quantum register. Effectively, the interaction with the environment is reduced. In particular, a sequence of $\pi$ pulses is…

Quantum Physics · Physics 2008-08-18 Götz S. Uhrig

The need for strategies able to accurately manipulate quantum dynamics is ubiquitous in quantum control and quantum information processing. We investigate two scenarios where randomized dynamical decoupling techniques become more…

Quantum Physics · Physics 2009-11-13 Lorenza Viola , Lea F. Santos

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

One of the most significant hurdles to be overcome on the path to practical quantum information processors is dealing with quantum errors. Dynamical decoupling is a particularly promising approach that complements conventional quantum error…

We present a scalable scheme to design optimized soft pulses and pulse sequences for coherent control of interacting quantum many-body systems. The scheme is based on the cluster expansion and the time dependent perturbation theory…

Quantum Physics · Physics 2007-05-23 Pinaki Sengupta , Leonid P. Pryadko

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

Dynamical decoupling as a quantum control strategy aims at suppressing quantum decoherence adopting the popular philosophy that the disorder in the unitary evolution of the open quantum system caused by environmental noises should be…

Quantum Physics · Physics 2018-01-17 Jun Jing , Ting Yu , Chi-Hang Lam , J. Q. You , Lian-Ao Wu

We apply reverse-engineering to find electromagnetic pulses that allow for the control of populations in quantum systems under dephasing and thermal noises. In particular, we discuss two-level systems given their importance in the…

Quantum Physics · Physics 2019-07-10 I. Medina , F. L. Semião

Relaxation effects impose fundamental limitations on our ability to coherently control quantum mechanical phenomena. In this letter, we establish physical limits on how closely can a quantum mechanical system be steered to a desired target…

Quantum Physics · Physics 2009-11-10 N. Khaneja , B. Luy , S. J. Glaser
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