Super-resolved time-frequency measurements of coupled phonon dynamics in a 2D quantum material

被引：1

作者：

Gentry, Christian ^{[1
,2
,3
]}

Liao, Chen-Ting ^{[1
,2
,3
]}

You, Wenjing ^{[1
,2
,3
]}

Ryan, Sinead A. ^{[1
,2
,3
]}

Varner, Baldwin Akin ^{[3
,4
]}

Shi, Xun ^{[1
,2
,3
]}

Guan, Meng-Xue ^{[9
]}

Gray, Thomas ^{[1
,2
,3
]}

Temple, Doyle ^{[4
]}

Meng, Sheng ^{[9
]}

Raschke, Markus ^{[1
,2
,3
]}

Rossnagel, Kai ^{[5
,6
,7
]}

Kapteyn, Henry C. ^{[1
,2
,3
,8
]}

Murnane, Margaret M. ^{[1
,2
,3
]}

Cating-Subramanian, Emma ^{[1
,2
,3
]}

机构：

[1] Univ Colorado, JILA, Boulder, CO 80309 USA

[2] NIST, Boulder, CO 80309 USA

[3] STROBE Sci & Technol Ctr, Boulder, CO 80309 USA

[4] Norfolk State Univ, Dept Phys, Norfolk, VA 23504 USA

[5] Univ Kiel, Inst Expt & Appl Phys, D-24098 Kiel, Germany

[6] Univ Kiel, KiNSIS, D-24098 Kiel, Germany

[7] DESY, Ruprecht Haensel Lab, D-22607 Hamburg, Germany

[8] KMLabs Inc, 4775 Walnut St,Suite 102, Boulder, CO 80301 USA

[9] Chinese Acad Sci, Inst Phys, Beijing 100190, Peoples R China

来源：

SCIENTIFIC REPORTS | 2022年 / 12卷 / 01期

关键词：

TEMPERATURE; WAVELETS; 1T-TASE2;

D O I：

10.1038/s41598-022-22055-w

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

Methods to probe and understand the dynamic response of materials following impulsive excitation are important for many fields, from materials and energy sciences to chemical and neuroscience. To design more efficient nano, energy, and quantum devices, new methods are needed to uncover the dominant excitations and reaction pathways. In this work, we implement a newly-developed superlet transform-a super-resolution time-frequency analytical method-to analyze and extract phonon dynamics in a laser-excited two-dimensional (2D) quantum material. This quasi-2D system, 1T-TaSe2, supports both equilibrium and metastable light-induced charge density wave (CDW) phases mediated by strongly coupled phonons. We compare the effectiveness of the superlet transform to standard time-frequency techniques. We find that the superlet transform is superior in both time and frequency resolution, and use it to observe and validate novel physics. In particular, we show fluence-dependent changes in the coupled dynamics of three phonon modes that are similar in frequency, including the CDW amplitude mode, that clearly demonstrate a change in the dominant charge-phonon couplings. More interestingly, the frequencies of the three phonon modes, including the strongly-coupled CDW amplitude mode, remain time- and fluence-independent, which is unusual compared to previously investigated materials. Our study opens a new avenue for capturing the coherent evolution and couplings of strongly-coupled materials and quantum systems.

引用

页数：8