arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2009.05025cond-mat.str-el
收藏

1$T$-TaSe$_{2}$中的相干声子及电荷密度波与莫特相的相互作用

Coherent phonons and the interplay between charge density wave and Mott phases in 1$T$-TaSe$_{2}$

Politecnico di Milano(米兰理工大学);University of Bath(巴斯大学);IFN-CNR(凝聚态物理研究所-国家研究委员会);Université de Lyon(里昂大学);ENS de Lyon(里昂高等师范学校);Université Claude Bernard(克洛德·贝尔纳大学);University of Bristol(布里斯托大学)

C. J. Sayers, H. Hedayat, A. Ceraso, F. Museur, M. Cattelan, L. S. Hart, L. S. Farrar, S. Dal Conte, G. Cerullo, C. Dallera, E. Da Como, E. Carpene

AI总结:

本研究结合TR-ARPES与TRR技术探究1$T$-TaSe₂中的相干声子振荡,明确了面内CDW振幅模与莫特相的关联,揭示了晶格自由度在该强关联体系中的重要作用。

摘要:

1$T$-TaSe$_{2}$是多种强关联相共存的体系,包括电荷密度波(CDWs)和低温下的反常莫特转变。本文结合时间分辨角分辨光电子能谱(TR-ARPES)和时间分辨反射率(TRR),研究了1$T$-TaSe$_{2}$中的相干声子振荡。飞秒激光脉冲的扰动触发了Γ点价带结合能的调制,该调制与莫特能隙相关,且其频率与面内CDW振幅模的频率一致。相比之下,TRR测量显示差分反射率的调制由多个频率组成,这些频率属于畸变的CDW晶格模。对比CDW转变温度附近相干声子与自发声子的温度依赖关系发现,与其他模式相比,CDW态受光激发扰动时,振幅模的强度更容易被抑制。本研究明确了1$T$-TaSe$_{2}$中面内CDW振幅模与莫特相的关联,凸显了晶格自由度的重要性。

英文摘要:

1$T$-TaSe$_{2}$ is host to coexisting strongly-correlated phases including charge density waves (CDWs) and an unusual Mott transition at low temperature. Here, we investigate coherent phonon oscillations in 1$T$-TaSe$_{2}$ using a combination of time- and angle-resolved photoemission spectroscopy (TR-ARPES) and time-resolved reflectivity (TRR). Perturbation by a femtosecond laser pulse triggers a modulation of the valence band binding energy at the $Γ$-point, related to the Mott gap, that is consistent with the in-plane CDW amplitude mode frequency. By contrast, TRR measurements show a modulation of the differential reflectivity comprised of multiple frequencies belonging to the distorted CDW lattice modes. Comparison of the temperature dependence of coherent and spontaneous phonons across the CDW transition shows that the amplitude mode intensity is more easily suppressed during perturbation of the CDW state by the optical excitation compared to other modes. Our results clearly identify the relationship of the in-plane CDW amplitude mode with the Mott phase in 1$T$-TaSe$_{2}$ and highlight the importance of lattice degrees of freedom.

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。

↑