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arXiv 1709.04426cond-mat.str-elcond-mat.mes-hall
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V2O3中绝缘体-金属转变的非平衡相先驱体

Non-equilibrium phase precursors to the insulator-metal transition in V2O3

Andrej Singer, Juan Gabriel Ramirez, Ilya Valmianski, Devin Cela, Nelson Hua, Roopali Kukreja, James Wingert, Olesya Kovalchuk, James M. Glownia, Marcin Sikiros… 展开作者

Andrej Singer, Juan Gabriel Ramirez, Ilya Valmianski, Devin Cela, Nelson Hua, Roopali Kukreja, James Wingert, Olesya Kovalchuk, James M. Glownia, Marcin Sikiroski, Matthieu Chollet, Martin Holt, Ivan K. Schuller, Oleg G. Shpyrko

摘要:

发现物质的新相是现代物理学的核心。在量子材料中,原子尺度相互作用的细微变化可以引起宏观性质的巨大变化,并驱动相变。尽管它们的重要性,支持相变的中尺度过程往往仍然难以捉摸,因为原子和电子的变化和热力学转变之间的时间尺度的巨大差异。在这里,我们光诱导和直接观察与X射线散射的超快增强的结构长程序中的原型莫特系统V2 O3。尽管晶体对称性的超快变化,但晶胞体积的变化慢一个数量级,并且与绝缘体到金属的转变相一致。时域中两个结构响应之间的解耦凸显了瞬时光致前体相的存在,该相与平衡中存在的两个结构相不同。X射线纳米显微镜显示,声学声子被困在纳米级块治理的超快过渡到前体相的动力学,而成核和金属域的生长决定的时间较慢的过渡到金属相。在电子跃迁完成之前长程序的增强表明了非平衡结构相在关联电子系统的电子相变过程中所起的关键作用。

英文摘要:

The discovery of novel phases of matter is at the core of modern physics. In quantum materials, subtle variations in atomic-scale interactions can induce dramatic changes in macroscopic properties and drive phase transitions. Despite their importance, the mesoscale processes underpinning phase transitions often remain elusive because of the vast differences in timescales between atomic and electronic changes and thermodynamic transformations. Here, we photoinduce and directly observe with x-ray scattering an ultrafast enhancement of the structural long-range order in the archetypal Mott system V2O3. Despite the ultrafast change in crystal symmetry, the change of unit cell volume occurs an order of magnitude slower and coincides with the insulator-to-metal transition. The decoupling between the two structural responses in the time domain highlights the existence of a transient photoinduced precursor phase, which is distinct from the two structural phases present in equilibrium. X-ray nanoscopy reveals that acoustic phonons trapped in nanoscale blocks govern the dynamics of the ultrafast transition into the precursor phase, while nucleation and growth of metallic domains dictate the duration of the slower transition into the metallic phase. The enhancement of the long-range order before completion of the electronic transition demonstrates the critical role the non-equilibrium structural phases play during electronic phase transitions in correlated electrons systems.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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