论文标题
强场浅色固体的时间和角度分辨的光电子光谱:绝热带图片的流行率
Time- and angle-resolved photoelectron spectroscopy of strong-field light-dressed solids: prevalence of the adiabatic band picture
论文作者
论文摘要
近年来,凝结物中的强场物理学通过激光穿压,以及通过非线性光 - 谐音相互作用(例如谐波产生)来控制材料特性的新方法。这些进步引起的潜在争议是,有时应该使用哪种频带图来解释强场实验:无野外带,绝热(瞬时)野外式带状频带,浮雕带或其他一些中间图片。在这里,我们尝试通过对时间和角度分辨光电子光谱(TR-ARPES)进行“强景激光泵式固体”的“理论实验”来解决此问题,这应该使得可以访问辐照材料的实际可观察带。令我们惊讶的是,我们发现绝热的频带图的生存良好,直至高场强度(〜10^12 w/cm^2),并且在较大的频率范围内(驱动波长为4000至800nm,keldysh参数范围为〜7)。我们得出的结论是,在一阶中,绝热瞬时频带应该是当磁场高度偏离固体且具有特征性能量尺度的材料的特征能量时,用于解释固体中超快电子动力学的标准蓝图。然后,我们讨论超过此图片的频段修饰的较弱效应,这些频段是非绝热的,这表明,通过使用双色字段,可以通过增强的灵敏度来探测与标准图像的偏差。我们的工作概述了固体中强场相互作用的物理学的清晰带图片,这对于设计和分析强场实验性可观察物以及制定简单的半经验模型应该很有用。
In recent years, strong-field physics in condensed-matter was pioneered as a novel approach for controlling material properties through laser-dressing, as well as for ultrafast spectroscopy via nonlinear light-matter interactions (e.g. harmonic generation). A potential controversy arising from these advancements is that it is sometimes vague which band-picture should be used to interpret strong-field experiments: the field-free bands, the adiabatic (instantaneous) field-dressed bands, Floquet bands, or some other intermediate picture. We here try to resolve this issue by performing 'theoretical experiments' of time- and angle-resolved photoelectron spectroscopy (Tr-ARPES) for a strong-field laser-pumped solid, which should give access to the actual observable bands of the irradiated material. To our surprise, we find that the adiabatic band-picture survives quite well, up to high field intensities (~10^12 W/cm^2), and in a wide frequency range (driving wavelengths of 4000 to 800nm, with Keldysh parameters ranging up to ~7). We conclude that to first order, the adiabatic instantaneous bands should be the standard blueprint for interpreting ultrafast electron dynamics in solids when the field is highly off-resonant with characteristic energy scales of the material. We then discuss weaker effects of modifications of the bands beyond this picture that are non-adiabatic, showing that by using bi-chromatic fields the deviations from the standard picture can be probed with enhanced sensitivity. Our work outlines a clear band picture for the physics of strong-field interactions in solids, which should be useful for designing and analyzing strong-field experimental observables and also to formulate simpler semi-empirical models.