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Related papers: Protecting the $\sqrt{SWAP}$ operation from genera…

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We can encode a qubit in the energy levels of a quantum system. Relaxation and other dissipation processes lead to decay of the fidelity of this stored information. Is it possible to preserve the quantum information for a longer time by…

Quantum Physics · Physics 2021-08-06 Zhaoyou Wang , Taha Rajabzadeh , Nathan Lee , Amir H. Safavi-Naeini

We study the correction of errors intervening in two-qubit dissipating into their own environments. This is done by resorting to local feedback actions with the aim of preserving as much as possible the initial amount of entanglement.…

Quantum Physics · Physics 2016-08-30 Morteza Rafiee , Alireza Nourmandipour , Stefano Mancini

We investigate quantum control of the dissipation of entanglement under environmental decoherence. We show by means of a simple two-qubit model that standard control methods - coherent or open-loop control - will not in general prevent…

Quantum Physics · Physics 2014-03-04 Sophie G. Schirmer , Allan I. Solomon

Theoretically understanding and experimentally characterizing and modifying the underlying Hamiltonian of a quantum system is of utmost importance in achieving high-fidelity quantum gates for quantum computing. In this work, we explore the…

We study the dynamics of entanglement in a two-qubit system interacting with a squeezed thermal bath via a dissipative system-reservoir interaction with the system and reservoir assumed to be in a separable initial state. The resulting…

Quantum Physics · Physics 2010-04-22 Subhashish Banerjee , V. Ravishankar , R. Srikanth

We explore a strategy for protecting the evolution of a qubit against the effects of environmental noise based on the application of controlled time-dependent perturbations. In the case of a purely decohering coupling, an explicit sequence…

Quantum Physics · Physics 2007-05-23 Lorenza Viola , Seth Lloyd

Dynamic quantum circuits integrate mid-circuit measurements and feed-forward operations to enable real-time classical processing and conditional quantum logic. These capabilities are central to key quantum protocols such as quantum error…

Quantum Physics · Physics 2026-05-15 Sumeet Shirgure , Siyuan Niu

We investigate the use of driven qubits coupled to a harmonic oscillator to implement a $\sqrt{i\mathrm{SWAP}}$-gate. By dressing the qubits through an external driving field, the qubits and the harmonic oscillator can be selectively…

Quantum Physics · Physics 2026-01-27 Alberto Hijano , Henri Lyyra , Juha T. Muhonen , Tero T. Heikkilä

Control of decoherence in open quantum systems has become a topic of great interest due to the emergence of quantum technologies that depend on quantum coherent effects. In this work, we investigate the decoherence dynamics of systems…

Quantum Physics · Physics 2025-04-04 Jitian Chen , Jakub Garwoła , Dvira Segal

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 consider a universal set of quantum gates encoded within a perturbed decoherence-free subspace of four physical qubits. Using second-order perturbation theory and a measuring device modeled by an infinite set of harmonic oscillators,…

Quantum entanglement is a crucial resource in quantum information processing, and protecting it against noise poses a significant challenge. This paper introduces two strategies for preserving qutrit-qutrit entanglement in the presence of…

Quantum Physics · Physics 2026-04-24 Xing Xiao , Wen-Rui Huang , Tian-Xiang Lu , Yan-Ling Li

We analyze the accuracy of quantum phase gates acting on "0-$\pi$ qubits" in superconducting circuits, where the gates are protected against thermal and Hamiltonian noise by continuous-variable quantum error-correcting codes. The gates are…

Quantum Physics · Physics 2020-07-24 Peter Brooks , Alexei Kitaev , John Preskill

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

Dense ensembles of spin qubits are valuable for quantum applications, even though their coherence protection remains challenging. Continuous dynamical decoupling can protect ensemble qubits from noise while allowing gate operations, but it…

Quantum Physics · Physics 2021-01-22 Guoqing Wang , Yi-Xiang Liu , Paola Cappellaro

Dynamical error suppression techniques are commonly used to improve coherence in quantum systems. They reduce dephasing errors by applying control pulses designed to reverse erroneous coherent evolution driven by environmental noise.…

We analyze the quantum process tomography (QPT) in the presence of decoherence, focusing on distinguishing local and non-local decoherence mechanisms for a two-partite system from experimental QPT data. In particular, we consider the…

Quantum Physics · Physics 2015-05-13 A. G. Kofman , A. N. Korotkov

Using both simulation and experiment, we investigate the robustness of dynamical decoupling sequences to pulse errors: rotation errors and detuning errors. Whereas prior work examined the effect of errors on coherence times, here we show…

A protocol based on quantum error correction based characterization of quantum dynamics (QECCD) is developed for quantum process tomography on a two-qubit system interacting dissipatively with a vacuum bath. The method uses a 5-qubit…

Quantum Physics · Physics 2017-02-09 S. Omkar , R. Srikanth , Subhashish Banerjee , Anil Shaji

Quantum dynamical decoupling is a procedure to cancel the effective coupling between two systems by applying sequences of fast actuations, under which the coupling Hamiltonian averages out to leading order(s). One of its prominent uses is…

Quantum Physics · Physics 2022-01-25 Michiel Burgelman , Paolo Forni , Alain Sarlette