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Dynamically correcting for unwanted interactions between a quantum system and its environment is vital to achieving the high-fidelity quantum control necessary for a broad range of quantum information technologies. In recent work, we…

Quantum Physics · Physics 2018-07-11 Junkai Zeng , Edwin Barnes

We investigate how to protect quantum correlations for two qubits each locally interacting with its own non-Markovian environment by making use of bang-bang pulses. It is shown that the quantum discord dynamics presents the phenomenon of…

Quantum Physics · Physics 2012-08-28 Hang-Shi Xu , Jing-Bo Xu

We revisit the problem of switching off unwanted phase evolution and decoherence in a single two-state quantum system in the light of recent results on random dynamical decoupling methods [L. Viola and E. Knill, Phys. Rev. Lett. {\bf 94},…

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

The presence of decoherence in quantum computers necessitates the suppression of noise. Dynamically corrected gates via specially designed control pulses offer a path forward, but hardware-specific experimental constraints can cause…

Quantum Physics · Physics 2022-05-31 Utkan Güngördü , J. P. Kestner

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 report the realization, using nuclear magnetic resonance techniques, of the first quantum computer that reliably executes an algorithm in the presence of strong decoherence. The computer is based on a quantum error avoidance code that…

Quantum Physics · Physics 2007-05-23 Jason E. Ollerenshaw , Daniel A. Lidar , Lewis E. Kay

We re-examine a scheme generalized by [R. Finkelstein et al, Phys. Rev. X 11, 011008 (2021)], whose original purpose was to remove the effects of static Doppler broadening from an ensemble of non-interacting two-level systems (qubits). This…

Quantum Physics · Physics 2023-02-09 Fernando Quijandría , Jason Twamley

We introduce and implement GraphDD: an efficient method for real-time, circuit-specific, optimal embedding of dynamical decoupling (DD) into executable quantum algorithms. We demonstrate that for an arbitrary quantum circuit, GraphDD…

Quantum Physics · Physics 2025-06-13 Paul Coote , Roman Dimov , Smarak Maity , Gavin S. Hartnett , Michael J. Biercuk , Yuval Baum

The thesis is contributed to the study of the decoherence dynamics of dissipative qubit systems. We reveal the profound impact of the formation of a bound state between the qubit and its local environment on the decoherence dynamics of…

Quantum Physics · Physics 2010-07-29 Qing-Jun Tong

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

The decoherence of quantum correlation is investigated in the Heisenberg spin system with the asymmetric anisotropic interactions. The quantum entanglement and discord are used to quantify the quantumness of the correlations. By the…

Quantum Physics · Physics 2012-08-09 Xiang Hao , Chunlan Ma , Jinqiao Sha

We present an analytical solution for classical correlation, defined in terms of linear entropy, in an arbitrary $d\otimes 2$ system when the second subsystem is measured. We show that the optimal measurements used in the maximization of…

Quantum Physics · Physics 2015-09-07 Zhihao Ma , Zhihua Chen , Felipe F. Fanchini , Shao-Ming Fei

The protection of qubit coherence is an essential task in order to build a practical quantum computer able to manipulate, store and read quantum information with a high degree of fidelity. Recently, it has been proposed to increase the…

Quantum Physics · Physics 2022-05-26 Sylvain Bertaina , Hervé Vezin , Hans De Raedt , Irinel Chiorescu

Quantum bits or qubits naturally decohere by becoming entangled with uncontrollable environments. Dynamical decoupling is thereby required to disentangle qubits from an environment by periodically reversing the qubit bases, but this causes…

Quantum Physics · Physics 2020-02-26 Yuhei Sekiguchi , Yusuke Komura , Hideo Kosaka

Quantum error correction provides a path to large-scale quantum computers, but is built on challenging assumptions about the characteristics of the underlying errors. In particular, the mathematical assumption of independent errors in…

Quantum Physics · Physics 2017-12-15 C. L. Edmunds , C. Hempel , R. Harris , H. Ball , V. Frey , T. M. Stace , M. J. Biercuk

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

We propose a novel symmetrization procedure to beat decoherence for oscillator-assisted quantum gate operations. The enacted symmetry is related to the global geometric features of qubits transformation based on ancillary oscillator modes,…

Quantum Physics · Physics 2009-11-10 Li-Xiang Cen , Paolo Zanardi

Recently several quantum search algorithms based on quantum walks were proposed. Those algorithms differ from Grover's algorithm in many aspects. The goal is to find a marked vertex in a graph faster than classical algorithms. Since the…

Quantum Physics · Physics 2012-05-18 G. Abal , R. Donangelo , F. L. Marquezino , A. C. Oliveira , R. Portugal

Due to omnipresent environmental interferences, quantum coherences inevitably undergo irreversible transformations over certain time-scales, thus leading to the loss of encoded information. This process, known as decoherence, has been a…

Quantum Physics · Physics 2014-06-19 Swathi S. Hegde , T. S. Mahesh

We address the system-reservoir dynamics of classical and quantum correlations in the decoherence phenomenon, regarding a two qubit composite system interacting with two independent environments. The most common noise channels (amplitude…

Quantum Physics · Physics 2011-12-02 J. Maziero , T. Werlang , F. F. Fanchini , L. C. Celeri , R. M. Serra