Strongly correlated materials exhibit intriguing properties caused by intertwined microscopic interactions that are hard to disentangle in equilibrium. Employing non-equilibrium time-resolved photoemission spectroscopy on the quasi-two-dimensional transition-metal dichalcogenide 1\emph{T}-TaS$_2$, we identify a spectroscopic signature of doubly occupied sites (doublons) that reflects fundamental Mott physics. Doublon-hole recombination is estimated to occur on time scales of electronic hopping $\hbar/J\approx$~14~fs. Despite strong electron-phonon coupling the dynamics can be explained by purely electronic effects captured by the single band Hubbard model under the assumption of weak hole doping, in agreement with our static sample characterization. This sensitive interplay of static doping and vicinity to the metal-insulator transition suggests a way to modify doublon relaxation on the few femtosecond time scale.

中文翻译：

---

光激发的1T-TaS $ _2 $中的超快doublon动力学

高度相关的材料表现出由交织在一起的微观相互作用引起的有趣特性，而这些相互作用很难在平衡中解开。通过在准二维过渡金属二卤化二硫化锡1 \ emph {T} -TaS $ _2 $上使用非平衡时间分辨的光发射光谱，我们确定了反映了基本Mott物理学的双重占据位点（双核）的光谱特征。估计双链空穴重组发生在电子跳跃$ \ hbar / J \ approx $〜14〜fs的时间尺度上。尽管有很强的电子-声子耦合，但动力学仍可以由单带Hubbard模型在弱空穴掺杂的假设下捕获的纯电子效应来解释，这与我们的静态样品表征相符。