Qingyuan Fan
Ph.D. Student in Materials Science and Engineering, admitted Autumn 2019
Bio
Ph.D Student, Dept. of Materials Science and Engineering, Stanford 09.2019 - present
Undergraduate, Zhejiang University 2015-2019
Visiting Student Researcher, Aaron Lindenberg's group, Dept. of Materials Science and Engineering, Stanford 07.2018-09.2018
All Publications
-
Ultrafast Wavefront Shaping via Space-Time Refraction
ACS PHOTONICS
2023
View details for DOI 10.1021/acsphotonics.3c00498
View details for Web of Science ID 001021440200001
-
Ultrafast Optomechanical Strain in Layered GeS.
Nano letters
2023
Abstract
Strong coupling between light and mechanical strain forms the foundation for next-generation optical micro- and nano-electromechanical systems. Such optomechanical responses in two-dimensional materials present novel types of functionalities arising from the weak van der Waals bond between atomic layers. Here, by using structure-sensitive megaelectronvolt ultrafast electron diffraction, we report the experimental observation of optically driven ultrafast in-plane strain in the layered group IV monochalcogenide germanium sulfide (GeS). Surprisingly, the photoinduced structural deformation exhibits strain amplitudes of order 0.1% with a 10 ps fast response time and a significant in-plane anisotropy between zigzag and armchair crystallographic directions. Rather than arising due to heating, experimental and theoretical investigations suggest deformation potentials caused by electronic density redistribution and converse piezoelectric effects generated by photoinduced electric fields are the dominant contributors to the observed dynamic anisotropic strains. Our observations define new avenues for ultrafast optomechanical control and strain engineering within functional devices.
View details for DOI 10.1021/acs.nanolett.2c05048
View details for PubMedID 36898060