Recently, Professor Lifa Zhang from the School of Physics and Technology published a paper in the top international journal "Nano Letters" titled Propagating Chiral Phonons in Three-Dimensional Materials. The first author of the paper is Hao Chen, a PhD student in Professor Zhang’s research team, and the corresponding authors are Professor Lifa Zhang and Professor Shengyuan Yang of Singapore University of Technology and Design.
Chiral phonons were initially proposed and experimentally verified in two-dimensional systems. Their intriguing effects have generated profound impacts on multiple research fields. However, all chiral phonons reported to date are constrained to be local, in the sense that their group velocities vanish identically. Here, we propose the concept of propagating chiral phonons, which can transport the information on chirality and angular momentum. We demonstrate their existence in materials such as WN2 and propose an experimental setup to detect the unique feature of propagating chiral phonons. Our work endows chiral phonons with a crucial character——the ability to propagate and transport quantized information and opens the possibility to design novel phononic quantum devices.
Professor Lifa Zhang and his collaborators first predicted chiral phonons in 2015, which was later verified by experiments. Subsequently, the folding of chiral phonons, elliptical polarization chiral valley phonons, and one-step excitation of chiral phonons have been proposed. Through cooperative experiments, they discovered the entanglement of chiral phonons and photons, and the brightening of dark excitons by chiral phonons. He has published dozens of papers on chiral phonons in world-class journals such as Science, Nat. Phys., PRL, Nano Lett., ACS Nano, etc., which has attracted widespread attention from domestic and foreign peers.