Available control in dynamical decoupled quantum systems  

作　　者：Yu Pan ZaiRong Xi Wei Cui 

机构地区：[1]Chinese Acad Sci, Inst Syst Sci, Acad Math & Syst Sci, Key Lab Syst & Control, Beijing 100190, Peoples R China

出　　处：《Chinese Science Bulletin》2012年第18期2228-2232,共5页

基　　金：supported by the National Natural Science Foundation of China(60774099,60821091,61134008)

摘　　要：Dynamical decoupling (DD) eliminates qubit-bath coupling by applying a sequence of instantaneous pulses.While qubit-bath couplings generally lead to qubit relaxation and dephasing,qubit-qubit couplings are often used to manipulate or control quantum states.We investigate the available control operations in two DD schemes,named periodic DD (PDD) and Uhrig DD (UDD),to see whether universal quantum computation can be realized in these decoupled systems.We find that universal control is possible using Heisenberg interaction in both periodically decoupled system and Uhrig decoupled system,and the available control operations under two kinds of DD sequences obey the same commutation relation.In the UDD case,we also derive a rough bound for control errors.Dynamical decoupling （DD） eliminates qubit-bath coupling by applying a sequence of instantaneous pulses. While qubit-bath cou- plings generally lead to qubit relaxation and dephasing, qubit-qubit couplings are often used to manipulate or control quantum states. We investigate the available control operations in two DD schemes, named periodic DD （PDD） and Uhrig DD （UDD）, to see whether universal quantum computation can be realized in these decoupled systems. We find that universal control is possible using Heisen- berg interaction in both periodically decoupled system and Uhrig decoupled system, and the available control operations under two kinds of DD sequences obey the same commutation relation. In the UDD case, we also derive a rough bound for control errors.

关 键 词：控制操作 量子系统 动力学 解耦 脉冲序列 量子计算 约束控制 量子位 

分 类 号：O413.1[理学—理论物理]