光激发一维离子 Hubbard 模型中碰撞电离的新途径
A new pathway to impact ionization in a photo-excited one-dimensional ionic Hubbard model
AI总结：
该研究用含时 Lanczos 方法模拟瞬态激光作用下半填充一维离子 Hubbard 模型，发现离子势能释放及同阶光子激发态干涉可驱动碰撞电离。
摘要：
我们利用含时 Lanczos 方法，研究半填充一维离子 Hubbard 模型在瞬态激光脉冲影响下的非平衡动力学，体系处于 Mott 绝缘区深处。在平衡态下，增大 Mott 区中的交错势会减小 Mott 隙并展宽 Hubbard 带，从而为碰撞电离创造有利条件。激光激发后，我们观察到碰撞电离，其发生同时取决于交错势和激光泵浦频率。通过分析动能、离子能和 Coulomb 相互作用能的时间演化，我们识别出一种新的碰撞电离机制：过剩的离子势能被转化为额外的双占据，这不同于由过剩动能驱动该过程的传统机制。我们进一步表明，碰撞电离源于同阶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。
英文摘要：
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.
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。
