标题： 一种光激发一维离子 Hubbard 模型中影响电离的新途径 显示英文标题

标题： A new pathway to impact ionization in a photo-excited one-dimensional ionic Hubbard model

摘要： 使用时变兰佐斯方法，我们在瞬态激光脉冲的影响下，研究了半填充一维离子哈伯德模型在莫特绝缘体区域深处的非平衡动力学。 在平衡状态下，增加莫特区域中的交替势会减小莫特能隙并展宽哈伯德带，为碰撞电离创造了有利条件。 激光激发后，观察到碰撞电离，其发生取决于交替势和激光泵浦频率。 通过分析动能、离子和库仑相互作用能量的时间演化，我们发现了一种新的碰撞电离机制，其中过量的离子势能转化为额外的双占据态，不同于传统的机制，传统机制中过量的动能驱动这一过程。 我们进一步表明，碰撞电离源于由相同阶数光子激发所驱动的激发态之间的干涉。 这些结果为在强关联电子系统中实现碰撞电离提供了一条新途径。 显示英文摘要

摘要： Using the time-dependent Lanczos method, we study the non-equilibrium dynamics of the half-filled one-dimensional ionic Hubbard model, deep within the Mott insulating regime, under the influence of a transient laser pulse. In equilibrium, increasing the staggered potential in the Mott regime reduces the Mott gap and broadens the Hubbard bands, creating favorable conditions for impact ionization. After laser excitation, impact ionization is observed, with its occurrence depending on both the staggered potential and the laser pump frequency. By analyzing the time evolution of the kinetic, ionic, and Coulomb interaction energies, we identify a novel mechanism for impact ionization, in which excess ionic potential energy is converted into additional double occupancy-distinct from the conventional mechanism where excess kinetic energy drives this process. We further show that impact ionization arises from interference between excited states driven by photon excitation of the same order. These results present a new pathway for realizing impact ionization in strongly correlated electron systems.