论文标题
Spin-1/2各向同性海森堡簇中的量子疤痕
Quantum scars in spin-1/2 isotropic Heisenberg clusters
论文作者
论文摘要
我们研究了外部田地对Spin 1/2各向同性海森堡簇中特征状态能量水平和塔的统计数据的影响，包括链，梯子，正方形和三角形晶格。在一个方向上存在统一场的情况下，系统的SU（2）对称性使几乎整个光谱由大量具有相同水平间距的塔组成。有限簇上的确切对角线化表明，其他两个方向的随机横向场驱动了从泊松到Wigner-dyson分布的水平统计量，其平均水平间距比不同值，表明从集成性到非凝性的过渡。但是，对于三种类型的簇，发现最大的塔仍然容纳大约甚至对称性，从而导致量子疤痕。值得注意的是，非热的状态涵盖了Greenberger-Horn-Zeilinger和W状态，该状态保持了复兴的特征，而Neel状态在动态过程中衰减很快。另外，提出了一些用于实验检测的动态方案。我们的发现揭示了对有限尺寸量子自旋簇免疫的量子信息处理的可能性。
We investigate the influence of the external fields on the statistics of energy levels and towers of eigenstates in spin-1/2 isotropic Heisenberg clusters, including chain, ladder, square and triangular lattices. In the presence of uniform field in one direction, the SU(2) symmetry of the system allows that almost whole spectrum consists of a large number of towers with identical level spacing. Exact diagonalization on finite clusters shows that random transverse fields in other two directions drive the level statistics from Poisson to Wigner-Dyson distributions with different values of mean level spacing ratio, indicating the transition from integrability to non-integrability. However, for the three types of clusters, it is found that the largest tower still hold approximately even the symmetry is broken, resulting to a quantum scar. Remarkably, the non-thermalized states cover the Greenberger-Horn-Zeilinger and W states, which maintain the feature of revival while a Neel state decays fast in the dynamic processes. In addition, some dynamic schemes for experimental detection are proposed. Our finding reveals the possibility of quantum information processing that is immune to the thermalization in finite size quantum spin clusters.
