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arXiv 1611.04367cond-mat.stat-mech
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含时磁场驱动的O(N)矢量模型的非平衡标度

Off-equilibrium scaling driven by a time-dependent magnetic field in O(N) vector models

Stefano Scopa

摘要:

本文研究了具有O($N$)对称性的自旋系统在$2 < d < 4$空间维数中的非平衡动力学,该系统是由缓慢变化的随时间变化的磁场$h(t,t_s) \sim t/t_s$引起的,$t_s$是一个时间尺度,在临界温度$T = T_c$和低于临界温度$T < T_c$时都是如此.在展示了一般理论之后,我们展示了非平衡标度,并正式计算了大$N$极限下的关联函数。当磁场$h(t,t_s)$在相变周期性变化时,我们推导出磁滞回线面积和系统所做磁功的非平衡标度关系。我们还研究了关联函数中的第一个偏离平衡行为,以检验指数方法的一致性。

英文摘要:

We investigate the off-equilibrium dynamics of a spin system with O($N$) symmetry in $2 < d < 4$ spatial dimensions arising by the presence of a slowly varying time-dependent magnetic field $h(t,t_s) \sim t/t_s$, $t_s$ is a time scale, at the critical temperature $T = T_c$ and below it $T < T_c$. After showing the general theory, we demonstrate the off-equilibrium scaling and we formally compute the correlation functions in the limit of large $N$. We derive the off-equilibrium scaling relations for the hysteresis loop area and for the magnetic work done by the system when the magnetic field $h(t,t_s)$ is varied across the phase transitions cyclically in time. We also investigate the first deviations from the equilibrium behavior in the correlation functions checking the consistence for an exponential approach.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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