Asymptotically noise decoupling for Markovian open quantum systems

作者:Zhang Jing*; Wu Re Bing; Li Chun Wen; Tarn Tzyh Jong; Wu Jian Wu
来源:Physical Review A, 2007, 75(2): 022324.
DOI:10.1103/PhysRevA.75.022324

摘要

The noise decoupling problem is investigated for general N-level Markovian open quantum systems. First, the concept of Cartan decomposition of the Lie algebra su(N) is introduced as a tool of designing control Hamiltonians. Next, under certain assumptions, it is shown that a part of variables of the coherence vector of the system density matrix can be asymptotically decoupled from the environmental noises. The resulting noise decoupling scheme is applied to one-qubit, qutrit, and two-qubit quantum systems, by which the coherence evolution of the one-qubit and qutrit systems can always be asymptotically preserved, while, for two-qubit systems, our findings indicate that evolution of some variables can be preserved only for some initial states.