论文标题
精确的和非脱颖而出的Fermi-Pasta-ulam-tsingou复发
Exact and non-exact Fermi-Pasta-Ulam-Tsingou recurrences in a Heisenberg ferromagnet
论文作者
论文摘要
我们通过利用其对非线性Schrödinger方程（NLSE）的量规格来可视化Fermi-pasta-ulam-tsingou（fput）复发（fput）复发（fput）复发（HF）自旋链。我们讨论了自旋链中两种类型的空间周期性的呼吸激励，它们与：（i）Akhmedieev喘口气，以及（ii）Galilean改变了Akhmedieev呼吸。从最初和最终状态相同的意义上，前者的复发是准确的。在后来，自旋链在恢复过程中经历了额外的全局旋转，这使得初始状态和最终状态可区分。然而，复杂的解决方案（i）和（ii）在复发过程中仍显示出定义的E相移。 HF旋转链和NLSE之间的一对一对应关系似乎由于FPUT复发的障碍而缺少。
We visualize the Fermi-Pasta-Ulam-Tsingou (FPUT) recurrence in a classical Heisenberg ferromagnetic (HF) spin chain by exploiting its gauge eq uivalence to the nonlinear Schrödinger equation (NLSE). We discuss two types of spatially periodic breather excitations in the spin chain, that are associated with: (I) Akhmediev breather, and (II) Galilean transformed Akhmediev breather. The recurrence in the former is exact in the sense that the initial and final states are identical. In the later, the spin chain undergoes an additional global rotation during the rec urrence process, which makes the initial and final states distinguishable. Both the complex solutions (I) and (II) nevertheless show a definit e phase shift during the recurrence process. A one-to-one correspondence between HF spin chain and the NLSE seems missing by virtue of the clo seness of the FPUT recurrence.
