次近邻相互作用下海森堡链的保真度和量子相变
Fidelity and Quantum phase transition for the Heisenberg chain with the next-nearest-neighbor interaction
摘要：
本文研究了具有次近邻相互作用的海森堡链（或$J_1-J_2$模型）的保真度，并分析了它与量子相变的关系。我们计算了基态之间的保真度，发现对于有限尺寸系统，$J_1-J_2$模型的相变点不能用基态保真度很好地表征。相反，我们引入并计算第一激发态之间的保真度。我们的结果表明，即使对于小尺寸系统，量子跃迁也可以用第一激发态的保真度来表征。
英文摘要：
In this paper, we investigate the fidelity for the Heisenberg chain with the next-nearest-neighbor interaction (or the $J_1-J_2$ model) and analyze its connections with quantum phase transition. We compute the fidelity between the ground states and find that the phase transition point of the $J_1-J_2$ model can not be well characterized by the ground state fidelity for finite-size systems. Instead, we introduce and calculate the fidelity between the first excited states. Our results show that the quantum transition can be well characterized by the fidelity of the first excited state even for a small-size system.
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。
