Yang Wen, Liu Ren-Bao
Department of Physics, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong, China.
Phys Rev Lett. 2008 Oct 31;101(18):180403. doi: 10.1103/PhysRevLett.101.180403. Epub 2008 Oct 29.
The optimal N-pulse dynamical decoupling discovered by Uhrig for a spin-boson model [Phys. Rev. Lett. 98, 100504 (2007)10.1103/PhysRevLett.98.100504] is proved to be universal in suppressing to O(T;{N+1}) the pure dephasing or the longitudinal relaxation of a qubit (or spin 1/2) coupled to a generic bath in a short-time evolution of duration T. For suppressing the longitudinal relaxation, a Uhrig pi-pulse sequence can be generalized to be a superposition of the ideal Uhrig pi-pulse sequence as the core and an arbitrarily shaped pulse sequence satisfying certain symmetry requirements. The generalized Uhrig dynamical decoupling offers the possibility of manipulating the qubit while simultaneously combating the longitudinal relaxation.
乌里格（Uhrig）为自旋 - 玻色子模型发现的最优N脉冲动力学解耦[《物理评论快报》98, 100504 (2007)10.1103/PhysRevLett.98.100504]被证明在抑制持续时间为T的短时间演化中与一般热库耦合的量子比特（或自旋1/2）的纯退相或纵向弛豫至O(T;{N + 1})时具有通用性。为了抑制纵向弛豫，乌里格π脉冲序列可以推广为以理想乌里格π脉冲序列为核心与满足某些对称要求的任意形状脉冲序列的叠加。广义乌里格动力学解耦提供了在对抗纵向弛豫的同时操纵量子比特的可能性。
