Quantum quenches in the sine-Gordon model: A semiclassical approach.
Quantum quenches in the sine-Gordon model: A semiclassical approach.
复制标题
正弦戈登模型中的量子猝灭：一种半经典方法。
作者：
M. Kormos;G. Zaránd
我们在半经典近似下计算了Sine-Gordon模型中量子猝灭后关联函数的时间演化，对于产生低密度慢准粒子的小猝灭和慢猝灭有望得到精确的结果。我们通过复制最近对期望值松弛的形式因数计算的结果来证明这一点[B.Bertini，D.Schuricht，和F.H.L.Essler，J.Stat。机甲。(2014)P100351742-546810.1088/1742-5468/2014/10/P10035].推广这些结果，我们发现--在极小的准粒子速度的普遍极限下--大多数顶点算符的期望值不会衰减到零。我们给出了动态相关函数松弛的解析表达式，并证明了它们对于大的类时间间隔具有扩散行为。
We compute the time evolution of correlation functions after quantum quenches in the sine-Gordon model within the semiclassical approximation, which is expected to yield accurate results for small and slow quenches producing slow quasiparticles with low density. We demonstrate this by reproducing results of a recent form-factor calculation of the relaxation of expectation values [B. Bertini, D. Schuricht, and F. H. L. Essler, J. Stat. Mech. (2014) P100351742-546810.1088/1742-5468/2014/10/P10035]. Extending these results, we find that-in the universal limit of vanishingly small quasiparticle velocities-the expectation values of most vertex operators do not decay to zero. We give analytic expressions for the relaxation of dynamic correlation functions and show that they have diffusive behavior for large timelike separation.