Excitation and entanglement transfer versus spectral gap
Excitation and entanglement transfer versus spectral gap
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DOI：
10.1088/1367-2630/8/6/094
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发表时间：
2006-06-09
影响因子：
3.3
通讯作者：
Plenio, M. B.
中科院分区：
文献类型：
--
作者：
Hartmann, M. J.;Reuter, M. E.;Plenio, M. B.
我们把量子多体系统看作量子通道，研究了传输质量与系统基态和激发态之间的谱隙大小之间的关系。在我们的设置中，两个辅助系统在不同位置弱耦合到量子多体系统，我们研究了激发和量子信息从一个辅助系统到另一个辅助系统的传播。我们观察到两种不同的情况：如果差距大，则缓慢但完美的转移，否则快速但不完整的转移。我们提供了一个数值和分析方法，以及一个简化的物理模型来解释我们的研究结果。我们的研究结果与潜在的自旋链作为量子通道的概念，量子相变，并提供了不同的方法来表征这些。
We consider quantum many body systems as quantum channels and study the relation between the transfer quality and the size of the spectral gap between the system's ground and excited states. In our setup, two ancillas are weakly coupled to the quantum many body system at different sites, and we study the propagation of an excitation and quantum information from one ancilla to the other. We observe two different scenarios: a slow, but perfect transfer if the gap is large and a fast, but incomplete transfer otherwise. We provide a numerical and analytical approach as well as a simplified physical model explaining our findings. Our results relate the potential of spin chains acting as quantum channels to the concept of quantum phase transitions and offer a different approach to the characterization of these.