Asymptotically noise decoupling for Markovian open quantum systems
Jing Zhang, Re-Bing Wu, Chunwen Li, Tzyh‐Jong Tarn, Jianwu Wu · Physical Review A · 2007
The noise decoupling problem is investigated for general $N$-level Markovian open quantum systems. First, the concept of Cartan decomposition of the Lie algebra $\mathrm{su}(N)$ 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.