无规磁场下自旋-1/2海森堡链的量子关联与多体局域化相变  

Quantum Correlation and Many-Body Localization Phase Transition in Spin-1/2 Heisenberg Chain Under a Disordered Magnetic Field

在线阅读下载全文

作  者:湛明亮 揭泉林[1] 

机构地区:[1]武汉大学物理科学与技术学院,湖北武汉430072

出  处:《量子光学学报》2015年第3期189-196,共8页Journal of Quantum Optics

基  金:国家自然科学基金(10875087)

摘  要:本文用两格点的量子关联研究无序系统的多体局域化相变。利用精确对角化的数值方法计算了无规磁场下自旋-1/2海森堡链的相邻本征态的两格点量子失谐之差与量子纠缠之差。结果表明在遍历相,相邻本征态的两格点量子失谐之差随链长的增长而逐渐趋近于零;而在多体局域化相,随链长的增长仍保持相对较大的值,这是多体局域化本征态违背本征态热化假定的反映,因此,相邻本征态的两格点量子失谐之差是研究多体局域化相变的有效工具。同时,与相邻本征态的两格点量子纠缠之差相比,分析发现用有限系统的量子失谐研究多体局域化相变比量子纠缠更具有优势。In this paper,many-body localization phase transition of disordered system was studied by using quantum correlation of two lattice sites. With the method of exact diagonalization we calculated the difference of quantum discord and quantum entanglement of two lattice sites in spin -1/2 Heisenberg chain under a disordered magnetic field between two adjacent eigenstates. The result shewed that the difference of quantum discord of two lattice sites between two adjacent eigenstates decays to zero as the length of chain grows in ergodic phase, while it remains large in many-body localization phase, which is a reflection of violation of eigenstate thermalization hypothesis of many-body localization eigenstates, so the difference of quantum discord of two lattice sites between two adjacent eigenstates is a useful tool to study many-body localization phase transition. Meanwhile, compared with the difference of entanglement of two lattice sites between two adjacent eigenstates, the analysis showed that it has more advantages to study many-body localization phase transition by using quantum discord than quantum entanglement of finite system.

关 键 词:量子关联 无序系统 多体局域化相变 本征态热化假定 

分 类 号:O431[机械工程—光学工程]

 

参考文献:

正在载入数据...

 

二级参考文献:

正在载入数据...

 

耦合文献:

正在载入数据...

 

引证文献:

正在载入数据...

 

二级引证文献:

正在载入数据...

 

同被引文献:

正在载入数据...

 

相关期刊文献:

正在载入数据...

相关的主题
相关的作者对象
相关的机构对象