论文标题
在有限的量子淬灭期间,在扩展的哈伯德模型中形成自旋和电荷顺序
Formation of spin and charge ordering in the extended Hubbard model during a finite-time quantum quench
论文作者
论文摘要
我们通过从非相互作用状态开始研究电荷和自旋顺序的形成,并研究其在有限的电子相互作用的哈密顿量下如何随着时间的流逝而演变。我们考虑了一维,半填充的扩展哈伯德模型,我们在时间依赖性密度矩阵重质化组中求解。通过在现场和最近的邻居相互作用中采用线性有限的时间淬火,我们发现脉冲,中间和绝热的时间演变的存在。对于我们分析的淬灭,我们观察到达到绝热状态,取决于是否形成了电荷密度波(CDW)还是旋转密度波(SDW)。前者需要比后者慢,以防止在淬火期间进入纠缠的激发态。更有趣的是,在中间制度中,我们观察到纠缠熵的最初价值的增强,该价值在CDW排序的形成之前;在朝向SDW的淬火中看不到类似的增强。我们的发现还表明,通过打开最近的邻居相互作用,系统的整合性破坏并不会导致绝热近似值内的非平衡行为发生显着变化。
We investigate the formation of charge and spin ordering by starting from a non-interacting state and studying how it evolves in time under a Hamiltonian with finite electronic interactions. We consider the one-dimensional, half-filled extended Hubbard model, which we solve within time-dependent density matrix renormalization group. By employing linear finite-time quenches in the onsite and nearest-neighbor interactions, we find the existence of impulse, intermediate, and adiabatic regimes of time evolution. For the quenches we analyze, we observe that the adiabatic regime is reached with distinct ramping time scales depending on whether the charge density wave (CDW) or the spin density wave (SDW) is formed. The former needs to be slower than the latter to prevent entangled excited states from being accessed during the quench. More interestingly, in the intermediate regime, we observe an enhancement of the entanglement entropy with respect to its initial value, which precedes the formation of the CDW ordering; a similar enhancement is not seen in the quench towards SDW. Our findings also show that the breaking of the system integrability, by turning on the nearest-neighbor interactions, does not give rise to significant changes in the non-equilibrium behavior within the adiabatic approximation.