Investigation of the non-equilibrium state of strongly correlated materials by complementary ultrafast spectroscopy techniques
Investigation of the non-equilibrium state of strongly correlated materials by complementary ultrafast spectroscopy techniques
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DOI：
10.1088/1367-2630/abe272
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发表时间：
2021-03-01
影响因子：
3.3
通讯作者：
Carpene, E.
中科院分区：
文献类型：
--
作者：
Hedayat, H.;Sayers, C. J.;Carpene, E.
光致非热相变是强关联材料奇异非平衡物理的新范式。超短光脉冲可以通过复杂的微观相互作用将系统驱动到一个新的顺序，这些相互作用在平衡态下不会发生。超快光谱是一种独特的工具，可以用来揭示导致物质瞬变相的这种转变的潜在机制。然而，它们各自的特殊性往往不能提供有关身体问题的详尽图景。提高其性能的一个有效解决方案是整合不同的超快技术。这提供了一个从不同角度同时探索物理现象的机会，同时保持相同的实验条件。在此背景下，我们通过结合时间分辨反射率和时间和角度分辨光电子能谱进行了补充实验。我们通过研究1T-TiSe_2中的复电荷密度波(CDW)相证明了这种组合方法的优势。具体地说，我们展示了晶格自由度在该材料中建立和稳定CDW的关键作用。
Photoinduced non-thermal phase transitions are new paradigms of exotic non-equilibrium physics of strongly correlated materials. An ultrashort optical pulse can drive the system to a new order through complex microscopic interactions that do not occur in the equilibrium state. Ultrafast spectroscopies are unique tools to reveal the underlying mechanisms of such transitions which lead to transient phases of matter. Yet, their individual specificities often do not provide an exhaustive picture of the physical problem. One effective solution to enhance their performance is the integration of different ultrafast techniques. This provides an opportunity to simultaneously probe physical phenomena from different perspectives while maintaining the same experimental conditions. In this context, we performed complementary experiments by combining time-resolved reflectivity and time and angle-resolved photoemission spectroscopy. We demonstrate the advantage of this combined approach by investigating the complex charge density wave (CDW) phase in 1T-TiSe2. Specifically, we show the key role of lattice degrees of freedom to establish and stabilize the CDW in this material.