تقرير
Ultrafast symmetry control in photoexcited quantum dots
| العنوان: | Ultrafast symmetry control in photoexcited quantum dots |
|---|---|
| المؤلفون: | Guzelturk, Burak, Portner, Joshua, Ondry, Justin, Ghanbarzadeh, Samira, Tarantola, Mia, Jeong, Ahhyun, Field, Thomas, Chandler, Alicia M., Wieman, Eliza, Hopper, Thomas R., Watkins, Nicolas E., Yue, Jin, Cheng, Xinxin, Lin, Ming-Fu, Luo, Duan, Kramer, Patrick L., Shen, Xiaozhe, Reid, Alexander H., Borkiewicz, Olaf, Ruett, Uta, Zhang, Xiaoyi, Lindenberg, Aaron M., Ma, Jihong, Schaller, Richard, Talapin, Dmitri V., Cotts, Benjamin L. |
| سنة النشر: | 2024 |
| المجموعة: | Condensed Matter Physics (Other) |
| مصطلحات موضوعية: | Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Materials Science, Physics - Optics |
| الوصف: | Symmetry control is essential for realizing unconventional properties, such as ferroelectricity, nonlinear optical responses, and complex topological order, thus it holds promise for the design of emerging quantum and photonic systems. Nevertheless, fast and reversible control of symmetry in materials remains a challenge, especially for nanoscale systems. Here, we unveil reversible symmetry changes in colloidal lead chalcogenide quantum dots on picosecond timescales. Using a combination of ultrafast electron diffraction and total X-ray scattering, in conjunction with atomic-scale structural modeling and first-principles calculations, we reveal that symmetry-broken lead sulfide quantum dots restore to a centrosymmetric phase upon photoexcitation. The symmetry restoration is driven by photoexcited electronic carriers, which suppress lead off-centering for about 100 ps. Furthermore, the change in symmetry is closely correlated with the electronic properties as shown by transient optical measurements. Overall, this study elucidates reversible symmetry changes in colloidal quantum dots, and more broadly defines a new methodology to optically control symmetry in nanoscale systems on ultrafast timescales. Comment: 19 pages, 5 figures |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/2408.15464 |
| رقم الأكسشن: | edsarx.2408.15464 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |