In order to achieve the high-fidelity quantum control needed for a broad range of quantum information technologies, reducing the effects of noise and system inhomogeneities is an essential task. It is well known that a system can be decoupled from noise or made insensitive to inhomogeneous dephasing dynamically by using carefully designed pulse sequences based on square or delta-function waveforms such as Hahn spin echo or CPMG. However, such ideal pulses are often challenging to implement experimentally with high fidelity. Here, we uncover a new geometrical framework for visualizing all possible driving fields, which enables one to generate an unlimited number of smooth, experimentally feasible pulses that perform dynamical decoupling or dynamically corrected gates to arbitrarily high order. We demonstrate that this scheme can significantly enhance the fidelity of single-qubit operations in the presence of noise and when realistic limitations on pulse rise times and amplitudes are taken into account.In order to achieve the high-fidelity quantum control needed for a broad range of quantum information technologies, reducing the effects of noise and system inhomogeneities is an essential task. It is well known that a system can be decoupled from noise or made insensitive to inhomogeneous dephasing dynamically by using carefully designed pulse sequences based on square or delta-function waveforms such as Hahn spin echo or CPMG. However, such ideal pulses are often challenging to implement experimentally with high fidelity. Here, we uncover a new geometrical framework for visualizing all possible driving fields, which enables one to generate an unlimited number of smooth, experimentally feasible pulses that perform dynamical decoupling or dynamically corrected gates to arbitrarily high order. We demonstrate that this scheme can significantly enhance the fidelity of single-qubit operations in the presence of noise and when realistic limitations on pulse rise times and amplitudes are taken into account.

arXiv:1703.00816New Journal of PhysicsFeb 16, 201837 citations

Dynamical decoupling by shaped pulses with partial local control

Leonid P. Pryadko, Pinaki Sengupta, Daniel A. Lidar +1 more

Bulletin of the American Physical SocietyMar 21, 20050 citations

Geometric continuous dynamical decoupling with bounded controls

Pochung Chen

We develop a framework to implement the dynamical decoupling of open quantum systems using continuous pulse sequences. By exploiting the geometric perspective of the continuous dynamical decoupling, we show that the decoupling pulses can be intuitively designed in the basis of the structure function of the $\mathrm{SU}(n)$ corresponding to the control Hamiltonian. Several examples are given to illustrate the basic idea. We argue that in practice the efficiency of the decoupling is determined by the minimum attainable decoupling cycle time ${T}_{c}$ instead of the order of the discrete decoupling group.We develop a framework to implement the dynamical decoupling of open quantum systems using continuous pulse sequences. By exploiting the geometric perspective of the continuous dynamical decoupling, we show that the decoupling pulses can be intuitively designed in the basis of the structure function of the $\mathrm{SU}(n)$ corresponding to the control Hamiltonian. Several examples are given to illustrate the basic idea. We argue that in practice the efficiency of the decoupling is determined by the minimum attainable decoupling cycle time ${T}_{c}$ instead of the order of the discrete decoupling group.

arXiv:quant-ph/0507265Physical Review AFeb 24, 200620 citations

High-order dynamical decoupling

Zhenyu Wang, Ren‐Bao Liu

Cambridge University Press eBooksSep 5, 20130 citations

Protecting geometric gates by dynamical decoupling

Guofu Xu, Guilu Long

Dynamical decoupling is a promising approach to protect quantum information from decoherence. It averages out the noise by flipping the qubits. In this paper, we demonstrate the protection of geometric gates by using dynamical decoupling with trapped ions. Specifically, a universal set of geometric gates is proposed with trapped ions and these gates are commutative with the decoupling group of the system. Our scheme combines the robust advantages of quantum holonomies and dynamical decoupling and hence can combat both control errors and decoherence. We also investigate the effects of dynamical decoupling pulse errors on the proposed geometric gates.Dynamical decoupling is a promising approach to protect quantum information from decoherence. It averages out the noise by flipping the qubits. In this paper, we demonstrate the protection of geometric gates by using dynamical decoupling with trapped ions. Specifically, a universal set of geometric gates is proposed with trapped ions and these gates are commutative with the decoupling group of the system. Our scheme combines the robust advantages of quantum holonomies and dynamical decoupling and hence can combat both control errors and decoherence. We also investigate the effects of dynamical decoupling pulse errors on the proposed geometric gates.

Physical Review AAug 22, 201471 citations

Topological dynamical decoupling

Jiang Zhang, Xiao-Dong Yu, Gui-Lu Long +1 more

arXiv:1909.10697Science China Physics Mechanics and AstronomySep 16, 201912 citations

\mathrm{SU}(n)

corresponding to the control Hamiltonian. Several examples are given to illustrate the basic idea. We argue that in practice the efficiency of the decoupling is determined by the minimum attainable decoupling cycle time

{T}_{c}

instead of the order of the discrete decoupling group.