量子XY自旋1/2链在原子存在下的猝灭动力学 横向场

是 否 +2 论坛币

k人 参与回答

经管之家送您一份

应届毕业生专属福利!

求职就业群

赵安豆老师微信：zhaoandou666

经管之家联合CDA

送您一个全额奖学金名额~ !

立即领取

感谢您参与论坛问题回答

经管之家送您两个论坛币！

+2 论坛币

摘要翻译：
本文研究了横向场中一维自旋1/2各向异性XY模型的量子动力学，当横向场或各向异性相互作用以缓慢而均匀的速率猝灭时。这两种淬火方案分别称为横向淬火和各向异性淬火。本文的重点是各向异性淬火方案，并与其他方案的结果进行了比较。在各向异性猝灭过程中，体系跨越弛豫时间发散的所有相图量子临界线。当参数接近临界值时，演化为非绝热演化，反之则为绝热演化。通过将多粒子系统映射到等效的Landau-Zener问题，计算了由非绝热跃迁产生的缺陷密度，通常发现缺陷密度以$1/\sqrt{\tau}$变化，其中$\tau$是淬火的特征时间尺度，支持Kibble-Zurek机制。有趣的是，在各向异性猝灭情况下，与横向猝灭情况相比，存在一个额外的非绝热跃迁，相应的概率在波矢的不公度值处达到峰值。在系统通过多临界点的特殊情况下，缺陷密度变化为$1/\tau^{1/6}$。最后态的冯诺依曼熵在淬灭速率下达到最大值，在淬灭速率附近，最终态的有序性由反铁磁转变为铁磁。
---
英文标题：
《Quenching Dynamics of a quantum XY spin-1/2 chain in presence of a
  transverse field》
---
作者：
Victor Mukherjee, Uma Divakaran, Amit Dutta and Diptiman Sen
---
最新提交年份：
2007
---
分类信息：

一级分类：Physics        物理学
二级分类：Statistical Mechanics        统计力学
分类描述：Phase transitions, thermodynamics, field theory, non-equilibrium phenomena, renormalization group and scaling, integrable models, turbulence
相变，热力学，场论，非平衡现象，重整化群和标度，可积模型，湍流
--
一级分类：Physics        物理学
二级分类：Quantum Physics        量子物理学
分类描述：Description coming soon
描述即将到来
--

---
英文摘要：
  We study the quantum dynamics of a one-dimensional spin-1/2 anisotropic XY model in a transverse field when the transverse field or the anisotropic interaction is quenched at a slow but uniform rate. The two quenching schemes are called transverse and anisotropic quenching respectively. Our emphasis in this paper is on the anisotropic quenching scheme and we compare the results with those of the other scheme. In the process of anisotropic quenching, the system crosses all the quantum critical lines of the phase diagram where the relaxation time diverges. The evolution is non-adiabatic in the time interval when the parameters are close to their critical values, and is adiabatic otherwise. The density of defects produced due to non-adiabatic transitions is calculated by mapping the many-particle system to an equivalent Landau-Zener problem and is generally found to vary as $1/\sqrt{\tau}$, where $\tau$ is the characteristic time scale of quenching, a scenario that supports the Kibble-Zurek mechanism. Interestingly, in the case of anisotropic quenching, there exists an additional non-adiabatic transition, in comparison to the transverse quenching case, with the corresponding probability peaking at an incommensurate value of the wave vector. In the special case in which the system passes through a multi-critical point, the defect density is found to vary as $1/\tau^{1/6}$. The von Neumann entropy of the final state is shown to maximize at a quenching rate around which the ordering of the final state changes from antiferromagnetic to ferromagnetic.
---
PDF链接：
https://arxiv.org/pdf/708.0278

扫码加我 拉你入群

请注明：姓名-公司-职位

以便审核进群资格，未注明则拒绝

分享0 收藏0 回帖

关键词：动力学 respectively Transitions Probability Statistical 方案 猝灭 等效 峰值 粒子系统