The Call of Modernity: Chinese School Songs in the Early Twentieth Century

This thesis studies the Chinese school songs (xuetangyuege 学堂乐歌) of the early twentieth century, a genre at the origins of Chinese musical modernity. I propose that it is necessary to study this subject through a political lens, particularly one that focuses on the questions of modernization and that is framed by the overall context of semicolonialism. I argue that school songs constituted the major musical activity of early Chinese modernity, manifesting a cultural imaginary of modern Chinese civilization marked by the building of a coherent nation. Chapter 1 analyzes the use of national landscape in school songs as a rhetorical strategy that aimed at the political goal of nation-building. Chapter 2 examines the discourse about women’s healthiness, femininity, and nationalist militarism in school songs.Master of Art

Nonreciprocal Spin Waves Driven by Left-Hand Microwaves

It is a conventional wisdom that a left-hand microwave cannot efficiently excite the spin wave (SW) in ferromagnets, due to the constraint of angular momentum conservation. In this work, we show that the left-hand microwave can drive nonreciprocal SWs in the presence of a strong ellipticity-mismatch between the microwave and precessing magnetization. A critical frequency is predicted, at which the left-hand microwave cannot excite SWs. Away from it the SW amplitude sensitively depends on the ellipticity of left-hand microwaves, in sharp contrast to the case driven by right-hand ones. By tuning the microwave frequency, we observe a switchable SW non-reciprocity in a ferromagnetic single layer. A mode-dependent mutual demagnetizing factor is proposed to explain this finding. Our work advances the understanding of the photon-magnon conversion, and paves the way to designing diode-like functionalities in nano-scaled magnonics

Magnetic skyrmion generation by reflective spin-wave focusing

We propose a method to generate magnetic skyrmions by focusing spin waves totally reflected by a curved film edge. Based on the principle of identical magnonic path length, we derive the edge contour that is parabolic and frequency-independent. Micromagnetic simulations are performed to verify our theoretical design. It is found that under proper conditions, magnetic droplet first emerges near the focal point where the spin-wave intensity has been significantly enhanced, and then converts to magnetic skyrmion accompanied by a change of the topological charge. The phase diagram about the amplitude and frequency of the driving field for skyrmion generation is obtained. Our finding would be helpful for the designment of spintronic devices combing the advantage of skyrmionics and magnonics.Comment: 5 pages, 5 figure