We consider quantum kinetics of an open quantum system in the presence of periodic fields designed to suppress the internal evolution and shield the system from generic low-frequency environment (refocusing or dynamical decoupling in application to multi-qubit systems). Assuming that the refocusing has order K, that is, for frozen environment the cumulant expansion of the evolution operator over the period tau begins with the term ~tau^(K+1), we trace the associated cancellations in the kernel of the quantum kinetic equation in the Floquet formalism and characterize the remaining decoherence processes.We consider quantum kinetics of an open quantum system in the presence of periodic fields designed to suppress the internal evolution and shield the system from generic low-frequency environment (refocusing or dynamical decoupling in application to multi-qubit systems). Assuming that the refocusing has order K, that is, for frozen environment the cumulant expansion of the evolution operator over the period tau begins with the term ~tau^(K+1), we trace the associated cancellations in the kernel of the quantum kinetic equation in the Floquet formalism and characterize the remaining decoherence processes.

arXiv:quant-ph/0510001Sep 30, 20050 citations

Semi-quantum Dynamics

David Finkelstein

Springer eBooksJan 1, 19960 citations

Quantum kinetics of an open system in the presence of periodic refocusing fields

Leonid P. Pryadko, Pinaki Sengupta

We consider quantum kinetics of an open quantum system in the presence of periodic fields designed to suppress the internal evolution and shield the system from a generic low-frequency environment (refocusing or dynamical decoupling in an application to multiqubit systems). Assuming that the refocusing has order $K$ , that is, for a frozen environment the cumulant expansion of the evolution operator over the period $\ensuremath{\tau}$ begins with the term $\ensuremath{\sim}{\ensuremath{\tau}}^{K+1}$, we trace the associated cancellations in the kernel of the quantum kinetic equation in the Floquet formalism and characterize the remaining decoherence processes.We consider quantum kinetics of an open quantum system in the presence of periodic fields designed to suppress the internal evolution and shield the system from a generic low-frequency environment (refocusing or dynamical decoupling in an application to multiqubit systems). Assuming that the refocusing has order $K$, that is, for a frozen environment the cumulant expansion of the evolution operator over the period $\ensuremath{\tau}$ begins with the term $\ensuremath{\sim}{\ensuremath{\tau}}^{K+1}$, we trace the associated cancellations in the kernel of the quantum kinetic equation in the Floquet formalism and characterize the remaining decoherence processes.

Physical Review BFeb 24, 200617 citations

Elements of Quantum Dynamics

Springer eBooksJun 7, 20060 citations

AN OPTIMIZED DYNAMICAL DECOUPLING STRATEGY TO SUPPRESS DECOHERENCE

Shuang Cong, Linping Chan, JIANXIU LIU

In this paper, we first present a brief derivation of the dynamical decoupling condition by means of designing control Hamiltonians, which is used to preserve arbitrary quantum states in the case of interactions with environment. According to different time intervals between the adjacent pulses, two important dynamical decoupling schemes: periodic dynamical decoupling (PDD) and Uhrig dynamical decoupling (UDD) are analyzed. Based on the comparison between PDD and UDD, we propose our optimized dynamical decoupling scheme with different time intervals between adjacent pulses which follow a normal distribution. At last numerical simulations are carried out in a three-level atom in Ξ -configuration, we select the non-diagonal element of density matrix as a reference index to compare the performances of suppressing the decoherence of these three strategies, and the results indicate that dynamical decoupling strategy proposed has better performances than that of PDD and UDD have under some low range of the loss of the quantum coherence.In this paper, we first present a brief derivation of the dynamical decoupling condition by means of designing control Hamiltonians, which is used to preserve arbitrary quantum states in the case of interactions with environment. According to different time intervals between the adjacent pulses, two important dynamical decoupling schemes: periodic dynamical decoupling (PDD) and Uhrig dynamical decoupling (UDD) are analyzed. Based on the comparison between PDD and UDD, we propose our optimized dynamical decoupling scheme with different time intervals between adjacent pulses which follow a normal distribution. At last numerical simulations are carried out in a three-level atom in Ξ -configuration, we select the non-diagonal element of density matrix as a reference index to compare the performances of suppressing the decoherence of these three strategies, and the results indicate that dynamical decoupling strategy proposed has better performances than that of PDD and UDD have under some low range of the loss of the quantum coherence.

International Journal of Quantum InformationOct 1, 20112 citations

K

, that is, for a frozen environment the cumulant expansion of the evolution operator over the period $\ensuremath{\tau}$ begins with the term $\ensuremath{\sim}{\ensuremath{\tau}}^{K+1}$, we trace the associated cancellations in the kernel of the quantum kinetic equation in the Floquet formalism and characterize the remaining decoherence processes.