论文标题
扰动的XXX自旋链中的准保存量
Quasi-conserved quantities in the perturbed XXX spin chain
论文作者
论文摘要
我们认为各向同性自旋1/2海森堡自旋链被局部翻译和su(2) - 激动扰动而薄弱。从不受干扰的模型的运动局部积分开始,我们对它们进行修改,以便为扰动模型获得准保存的运动积分(电荷)。据信,这种准固定的量是导致中间时间标准处的细息阶段存在的原因。我们发现,对于足够的局部扰动,只有前几个运动的积分才能促进到准固定的电荷,而高阶运动积分无法生存。
We consider the isotropic spin-1/2 Heisenberg spin chain weakly perturbed by a local translationally- and SU(2)-invariant perturbation. Starting from the local integrals of motion of the unperturbed model, we modify them in order to obtain quasi-conserved integrals of motion (charges) for the perturbed model. Such quasi-conserved quantities are believed to be responsible for the existence of the prethermalization phase at intermediate timescales. We find that for a sufficiently local perturbation only the first few integrals of motion can be promoted to the quasi-conserved charges, whereas higher-order integrals of motion do not survive.