论文标题
通过一维扩展哈伯德模型中的亚周脉冲来控制反转和时间反转的对称性
Controlling inversion and time-reversal symmetries by subcycle pulses in the one-dimensional extended Hubbard model
论文作者
论文摘要
具有高可控性，激光脉冲为我们对强相关的电子系统的理解做出了巨大贡献。但是，典型的多环形脉冲不能控制在新型量子相中起着重要作用的系统的对称性。在这里，我们证明了振荡在脉冲包膜内少于一个周期的亚周脉冲可以控制一维扩展哈伯德模型的电子状态中的反转和时反转对称性。使用超短型亚周脉冲，由于通过电场阶段瞬间引入的Aharonov-bohm通量，可以在光激发状态下生成稳定的电流（SEC）。因此，时间逆转对称性被打破。相比之下，宽的亚周脉冲不会诱导SEC，而是会产生电化极化，从而破坏了反转对称性。在光激发状态下的两个对称破坏都可以通过第二次谐波生成监测。这些发现为设计电子状态的对称性并打开了一个新的Subcycle-Pulse工程领域提供了一种新的方法。
Owning to their high controllability, laser pulses have contributed greatly to our understanding of strongly correlated electron systems. However, typical multicycle pulses do not control the symmetry of systems that plays an important role in the emergence of novel quantum phases. Here, we demonstrate that subcycle pulses whose oscillation is less than one period within a pulse envelope can control inversion and time-reversal symmetries in the electronic states of the one-dimensional extended Hubbard model. Using an ultrashort subcycle pulse, one can generate a steady electric current (SEC) in a photoexcited state due to an Aharonov-Bohm flux instantaneously introduced through the phase of an electric field. Consequently, time-reversal symmetry is broken. In contrast, a broad subcycle pulse does not induce SEC but instead generates electric polarization, thus breaking inversion symmetry. Both symmetry breakings in a photoexcited state can be monitored by second harmonic generation. These findings provide a new methodology for designing the symmetries of electronic states and open up a new field of subcycle-pulse engineering.
