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Maintaining quantum coherence is a crucial requirement for quantum computation; hence protecting quantum systems against their irreversible corruption due to environmental noise is an important open problem. Dynamical decoupling (DD) is an…

Quantum Physics · Physics 2011-03-24 Ashok Ajoy , Gonzalo A. Alvarez , Dieter Suter

Aperiodic dynamical decoupling (DD) sequences of $\pi$ pulses are of great interest to decoherence control and have been recently extended from single-qubit to two-qubit systems. If the environmental noise power spectrum is made available,…

Quantum Physics · Physics 2011-10-25 Yu Pan , Zai-Rong Xi , Jiangbin Gong

Two different dynamic decoupling strategies, the classic CPMG and the more recently proposed UDD protocol are compared in the context of magnetic resonance imaging (MRI). Both sequences were implemented on a 3T human MRI system and…

Medical Physics · Physics 2017-05-10 Sophie Schirmer , Jonathan Phillips

We present experimental measurements on a model quantum system that demonstrate our ability to dramatically suppress qubit error rates by the application of optimized dynamical decoupling pulse sequences in a variety of experimentally…

Avoiding the loss of coherence of quantum mechanical states is an important prerequisite for quantum information processing. Dynamical decoupling (DD) is one of the most effective experimental methods for maintaining coherence, especially…

Quantum Physics · Physics 2010-10-08 Gonzalo A. Alvarez , Ashok Ajoy , Xinhua Peng , Dieter Suter

We present a detailed experimental study of the Uhrig Dynamical Decoupling (UDD) sequence in a variety of noise environments. Our qubit system consists of a crystalline array of $^{9}$Be$^{+}$ ions confined in a Penning trap. We use an…

We analyze the suppression of decoherence by means of dynamical decoupling in the pure-dephasing spin-boson model for baths with power law spectra. The sequence of ideal $\pi$ pulses is optimized according to the power of the bath. We…

Quantum Physics · Physics 2010-03-15 S. Pasini , G. S. Uhrig

We utilize genetic algorithms to find optimal dynamical decoupling (DD) sequences for a single-qubit system subjected to a general decoherence model under a variety of control pulse conditions. We focus on the case of sequences with equal…

Quantum Physics · Physics 2013-11-13 Gregory Quiroz , Daniel A. Lidar

We investigate the optimal dynamical decoupling sequence for a qubit coupled to an ohmic environment. By analytically computing the derivatives of the decoherence function, the optimal pulse locations are found to satisfy a set of nonlinear…

Quantum Physics · Physics 2010-09-21 Yu Pan , Zairong Xi , Wei Cui

We investigate the nature of the pulse sequence so that unwanted transitions in quantum systems can be inhibited optimally. For this purpose we show that the sequence of pulses proposed by Uhrig [Phys. Rev. Lett. \textbf{98}, 100504 (2007)]…

Quantum Physics · Physics 2015-05-20 C. A. Schroeder , G. S. Agarwal

We study the suppression of qubit dephasing through Uhrig dynamical decoupling (UDD) in nontrivial environments modeled within the spin-boson formalism. In particular, we address the case of (i) a qubit coupled to a bosonic bath with…

Quantum Physics · Physics 2017-01-06 W. S. Teixeira , K. T. Kapale , M. Paternostro , F. L. Semião

We demonstrate the use of dynamic decoupling techniques to extend the coherence time of a single memory qubit by nearly two orders of magnitude. By extending the Hahn spin-echo technique to correct for unknown, arbitrary polynomial…

Quantum Physics · Physics 2011-02-10 David J. Szwer , Simon C. Webster , Andrew M. Steane , David M. Lucas

In the framework of nuclear magnetic resonance, we consider the general problem of the coherent control of a spin coupled to a bath by means of composite or continuous pulses of duration $\tau_\mathrm{p}$. We show explicity that it is…

Quantum Physics · Physics 2010-03-16 S. Pasini , P. Karbach , C. Raas , G. S. Uhrig

Dynamical decoupling (DD) is a technique for preserving the coherence of quantum mechanical states in the presence of a noisy environment. It uses sequences of inversion pulses to suppress the environmental perturbations by periodically…

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

One of the simplest and least resource-intensive methods to suppress decoherence for qubit operations, namely, dynamical decoupling (DD), is investigated for a broad range of realistic noise sources with time-retarded feedback. By way of…

Quantum Physics · Physics 2025-02-06 Kiyoto Nakamura , Joachim Ankerhold

The past decade has demonstrated increasing interests in using optimal control based methods within coherent quantum controllable systems. The versatility of such methods has been demonstrated with particular elegance within nuclear…

Quantum Physics · Physics 2015-05-18 Ivan I. Maximov , Niels Chr. Nielsen , Julien Salomon , Gabriel Turinici

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

We describe how the spin coherence time of a localized electron spin in solids, i.e. a solid state spin qubit, can be prolonged by applying designed electron spin resonance pulse sequences. In particular, the spin echo decay due to the…

Mesoscale and Nanoscale Physics · Physics 2011-03-14 W. M. Witzel , S. Das Sarma

A general strategy to maintain the coherence of a quantum bit is proposed. The analytical result is derived rigorously including all memory and back-action effects. It is based on an optimized $\pi$-pulse sequence for dynamic decoupling…

Quantum Physics · Physics 2011-11-09 Götz S. Uhrig

Concatenated dynamical decoupling (CDD) pulse sequences hold much promise as a strategy to mitigate decoherence in quantum information processing. It is important to investigate the actual performance of these dynamical decoupling…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 W. M. Witzel , S. Das Sarma
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