标题： 由对称单周期光脉冲激发形成的负温度态和相互作用反转 显示英文标题

标题： Negative-Temperature State Formed and Interactions Inverted by Symmetric Monocycle Optical Pulse Excitation

摘要： 受大振幅振荡电场脉冲激发的关联电子和电子-声子系统的激发态动力学被理论研究。 即使是对称的单周期脉冲也能诱导出"负温度"态以及电子-电子和电子-声子相互作用的反转。 这一事实通过精确对角化方法在二维一维三分之四填充强二聚化的扩展Peierls-Hubbard和Holstein模型的带绝缘相中被数值证明。 当总能量增量作为电场幅度的函数达到最大时，成键和反成键轨道的占据情况被反转以产生负温度态。 在此状态附近，时间平均的电子-电子和电子-声子关联函数与相互作用参数的依赖关系与基态中的相反。 显示英文摘要

摘要： The excited state dynamics of correlated electron and electron-phonon systems triggered by an oscillating electric-field pulse of large amplitude are theoretically investigated. A "negative-temperature" state and inversion of electron-electron and electron-phonon interactions are induced even by a symmetric monocycle pulse. This fact is numerically demonstrated, using the exact diagonalization method, in a band-insulator phase of one-dimensional three-quarter-filled strongly dimerized extended Peierls-Hubbard and Holstein models. When the total-energy increment is maximized as a function of the electric field amplitude, the occupancy of the bonding and antibonding orbitals is inverted to produce a negative-temperature state. Around this state, the dependences of time-averaged electron-electron and electron-phonon correlation functions on interaction parameters are opposite to those in the ground state.