2025-08-01 ミネソタ大学
＜関連情報＞
- https://cse.umn.edu/college/news/new-method-steer-electricity-atom-thin-metals-may-revolutionize-devices
- https://www.science.org/doi/10.1126/sciadv.adw7125
RuO2薄膜における異方性ひずみ緩和誘起の方向性超高速キャリアダイナミクス Anisotropic strain relaxation-induced directional ultrafast carrier dynamics in RuO2 films
Seung Gyo Jeong, In Hyeok Choi, Seungjun Lee, Jin Young Oh, […] , and Bharat Jalan
Science Advances Published:27 Jun 2025
DOI:https://doi.org/10.1126/sciadv.adw7125
Abstract
Ultrafast light-matter interactions inspire potential functionalities in picosecond optoelectronic applications. However, achieving directional carrier dynamics in metals remains challenging due to strong carrier scattering within a multiband environment, typically expected for isotropic carrier relaxation. In this study, we demonstrate epitaxial RuO2/TiO2 (110) heterostructures grown by hybrid molecular beam epitaxy to engineer polarization selectivity of ultrafast light-matter interactions via anisotropic strain engineering. Combining spectroscopic ellipsometry, x-ray absorption spectroscopy, and optical pump-probe spectroscopy, we revealed the strong anisotropic transient optoelectronic response at an excitation energy of 1.58 eV in strain-engineered RuO2/TiO2 (110) heterostructures along both in-plane [001] and [1 0] crystallographic directions. Theoretical analysis identifies strain-induced modifications in band nesting as the underlying mechanism for enhanced anisotropic carrier relaxation observed at this excitation energy. These findings establish epitaxial strain engineering as a powerful tool for tuning anisotropic optoelectronic responses with near-infrared excitations in metallic systems, paving the way for next-generation polarization-sensitive ultrafast optoelectronic devices.
