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We examine the effect of multilevels on decoherence and dephasing properties of a quantum system consisting of a non-ideal two level subspace, identified as the qubit and a finite set of higher energy levels above this qubit subspace. The…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 T. Hakioglu , K. Savran

Reliable processing of quantum information is a milestone to achieve for the deployment of quantum technologies. Uncontrolled, out-of-equilibrium sources of decoherence need to be characterized in detail for designing the control of quantum…

Quantum Physics · Physics 2023-10-26 Martin Kuffer , Analia Zwick , Gonzalo A. Alvarez

We study the spreading of a quantum-mechanical wavepacket in a one-dimensional tight-binding model with a noisy potential, and analyze the emergence of classical diffusion from the quantum dynamics due to decoherence. We consider a finite…

Quantum Physics · Physics 2015-05-13 Ariel Amir , Yoav Lahini , Hagai B. Perets

A scheme to implement a quantum computer subjected to decoherence and governed by an untunable qubit-qubit interaction is presented. By concatenating dynamical decoupling through bang-bang (BB) pulse with decoherence-free subspaces (DFSs)…

Quantum Physics · Physics 2007-05-23 Yong Zhang , Zheng-Wei Zhou , Bo Yu , Guang-Can Guo

Methods that preserve coherence broadly impact all quantum information processing and metrology applications. Dynamical decoupling methods accomplish this by protecting qubits in noisy environments but are typically constrained to the limit…

Dynamical decoupling is an important tool to counter decoherence and dissipation effects in quantum systems originating from environmental interactions. It has been used successfully in many experiments; however, there is still a gap…

Quantum Physics · Physics 2014-06-25 J. Z. Bernád , H. Frydrych

Quantum coherences are paramount resources for applications, such as quantum-enhanced light-harvesting or quantum computing, which are fragile against environmental noise. We here derive generalized quantum master equations using…

Quantum Physics · Physics 2020-09-03 Chahan M. Kropf

Noise that exhibits significant temporal and spatial correlations across multiple qubits can be especially harmful to both fault-tolerant quantum computation and quantum-enhanced metrology. However, a complete spectral characterization of…

A dynamical decoupling scheme for the deterrence of errors in the non-Markovian (usually corresponding to low temperature, short time, and strong coupling) regimes suitable for qubits constructed out of a multilevel structure is studied. We…

Quantum Physics · Physics 2007-05-23 K. Shiokawa , B. L. Hu

Decoherence is one of the most important obstacles that must be overcome in quantum information processing. It depends on the qubit-environment coupling strength, but also on the spectral composition of the noise generated by the…

Quantum Physics · Physics 2011-12-02 Gonzalo A. Alvarez , Dieter Suter

The loss of coherence is one of the main obstacles for the implementation of quantum information processing. The efficiency of dynamical decoupling schemes, which have been introduced to address this problem, is limited itself by the…

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

A major goal of developing high-precision control of many-body quantum systems is to realise their potential as quantum computers. Probably the most significant obstacle in this direction is the problem of "decoherence": the extreme…

We study a model of dephasing (decoherence) in a two-state quantum system (qubit) coupled to a bath of harmonic oscillators. An exact analytic solution for the reduced dynamics of a two-state system in this model has been obtained…

Quantum Physics · Physics 2015-05-28 V. G. Morozov , S. Mathey , G. Röpke

Realistic quantum computing is subjected to noise. A most important frontier in research of quantum computing is to implement noise-resilient quantum control over qubits. Dynamical decoupling can protect coherence of qubits. Here we…

Quantum Physics · Physics 2013-10-16 Gang-Qin Liu , Hoi Chun Po , Jiangfeng Du , Ren-Bao Liu , Xin-Yu Pan

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

We study the current noise spectrum of qubits under transport conditions in a dissipative bosonic environment. We combine (non-)Markovian master equations with correlation functions in Laplace-space to derive a noise formula for both weak…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 R. Aguado , T. Brandes

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 investigate the correspondence between classical noise and quantum environments. Although it has been known that the classical noise can be mapped to the quantum environments only for pure dephasing and infinite-temperature dissipation…

Quantum Physics · Physics 2024-12-31 Jiarui Zeng , Guo-Hao Xu , Weijie Huang , Yao Yao

Quantum information requires protection from the adverse affects of decoherence and noise. This review provides an introduction to the theory of decoherence-free subspaces, noiseless subsystems, and dynamical decoupling. It addresses…

Quantum Physics · Physics 2014-08-21 Daniel A. Lidar