论文标题
超快熔化和恢复激子绝缘子TA $ _ {2} $ nise $ _ {5} $中的集体订单
Ultrafast melting and recovery of collective order in the excitonic insulator Ta$_{2}$NiSe$_{5}$
论文作者
论文摘要
已提出了分层的Chalcogenide ta $ _ {2} $ nise $ _ {5} $，以在其基础状态下托管激发式冷凝物，该阶段可以提供一个独特的平台来在室温下研究和操纵多体状态。但是，确定对观察到的自发对称性破坏的主要显微镜贡献仍然具有挑战性，从而使辩论与基态特性有关。在这里，使用宽带超快光谱学我们研究了TA $ _ {2} $ nise $ _ {5} $的不平衡动力学，并证明了近边境范围内的短暂反射率与系统的低能物理学连接。我们使用此光学签名跟踪有序阶段的状态，确定高弹性光兴请表可以抑制此顺序。从低于50的FS淬火时间尺度和光诱导的相干声子模式的行为中，我们得出的结论是，电子相关性为激子秩序的形成提供了决定性的贡献。我们的结果铺平了在室温下对激子冷凝物进行超快控制的道路。
The layered chalcogenide Ta$_{2}$NiSe$_{5}$ has been proposed to host an excitonic condensate in its ground state, a phase that could offer a unique platform to study and manipulate many-body states at room temperature. However, identifying the dominant microscopic contribution to the observed spontaneous symmetry breaking remains challenging, perpetuating the debate over the ground state properties. Here, using broadband ultrafast spectroscopy we investigate the out-of-equilibrium dynamics of Ta$_{2}$NiSe$_{5}$ and demonstrate that the transient reflectivity in the near-infrared range is connected to the system's low-energy physics. We track the status of the ordered phase using this optical signature, establishing that high-fluence photoexcitations can suppress this order. From the sub-50 fs quenching timescale and the behaviour of the photoinduced coherent phonon modes, we conclude that electronic correlations provide a decisive contribution to the excitonic order formation. Our results pave the way towards the ultrafast control of an exciton condensate at room temperature.
