Quantum phononics is an important field of research because it deals with the study of phonons (quanta of vibrational energy in materials) in the context of quantum mechanics. Since the idea of phonons possessing pseudo-angular momentum was proposed a decade ago, chiral phonons have been studied for their potential in the development of new quantum information technologies. Multiple chiral phonon responses by helicity-resolved (HR)Raman have been demonstrated. Similar to optoelectronic manipulations of photons and electrons, researchers have therefore utilized incident photons with spin-angular-momentum (SAM) and orbital-angular-momentum (OAM) to probe such light-matter interactions. Various two-dimensional (2D) van der Waals (vdW) layer materials including 2D semiconductors (WS2, WSe2, MoS2, MoSe2) and 2D layered ferroelastic (FE) materials (WO2I2) will be presented here with focus of SAM manipulation. SAM-induced 2D semiconductor results serve as reference samples to verify the capabilities of spatially resolved HR Raman microscopy with sub-micron resolution. Next, 2D ferroelasticity (FE) stands out as the mechanical counterpart to ferromagnetism and ferroelectricity. It involves the switching of spontaneous lattice strain across multiple orientation states when subjected to mechanical stimuli. To probe 2D natural layered vdWs FE lateral domains in WO2I2 requires laser-based microscopic techniques for spatial resolution. In this talk, layered WO2I2 single crystal with FE lateral domains revealed by HR Raman microscopy is demonstrated with SAM HR Raman mapping. Lastly, I will introduce OAM manipulation of MoS2 and WSe2, revealing photoluminescence and phonon peak position shift, as preparation of current 2D opTiclab in the University of Wyoming and its research focus moving forward after the arrival of 9 tesla optical cryostat, hoping to bridge the gap between quantum technology and material science. Seeking collaboration with researchers here!
Dr. Tsai is an assistant professor at the University of Wyoming and leads the 2D optic lab with focus of low-dimensional magneto-phononics. He has obtained his PhD in University at Buffalo under Dr. Athos Petrou, and did postdoctoral in UT Austin, supervised by Dr. Chih-Kang (Ken) Shih. Prior to University of Wyoming, Tsai led a research group in Helmholtz Center at Berlin.